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IBM Informix Dynamic
Server Enterprise
Replication Guide
Version 9.4
March 2003
Part No. CT1T2NA
Note:
Before using this information and the product it supports, read the information in the
appendix entitled “Notices.”
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Contract with IBM Corp.
ii IBM Informix Dynamic Server Enterprise Replication Guide
Table of
Contents
Table of Contents
Introduction
In This Introduction . . . . . . . . . . . . . . . .
About This Manual . . . . . . . . . . . . . . . . .
Types of Users . . . . . . . . . . . . . . . . .
Software Dependencies . . . . . . . . . . . . . .
Assumptions About Your Locale. . . . . . . . . . .
Demonstration Databases . . . . . . . . . . . . .
New Features in Dynamic Server, Version 9.4 . . . . . . . .
Extensibility Enhancements . . . . . . . . . . . .
Functionality Improvements . . . . . . . . . . . .
Security Enhancements . . . . . . . . . . . . . .
Command-Line Changes . . . . . . . . . . . . .
Configuration Parameters and Environment Variable Changes
Documentation Conventions . . . . . . . . . . . . .
Typographical Conventions . . . . . . . . . . . .
Icon Conventions . . . . . . . . . . . . . . . .
Command-Line Conventions . . . . . . . . . . . .
Sample-Code Conventions . . . . . . . . . . . . .
Additional Documentation . . . . . . . . . . . . . .
Related Reading . . . . . . . . . . . . . . . . . .
Compliance with Industry Standards . . . . . . . . . .
IBM Welcomes Your Comments . . . . . . . . . . . .
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Section I
Introducing Enterprise Replication
Chapter 1
About IBM Informix Enterprise Replication
In This Chapter . . . . . . . . . .
IBM Informix Enterprise Replication . .
Asynchronous Data Replication. . .
Log-Based Data Capture . . . . .
High Performance . . . . . . .
High Availability . . . . . . . .
Consistent Information Delivery . .
Flexible Architecture . . . . . .
Centralized Administration . . . .
Network Encryption . . . . . .
How Enterprise Replication Replicates Data
Capturing Transactions . . . . .
Evaluating Data for Replication . . .
Distributing Data. . . . . . . .
Applying Replicated Data. . . . .
Chapter 2
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Overview of Enterprise Replication Administration
In This Chapter . . . . . . . . . . . . .
Overview of Enterprise Replication Administration
Enterprise Replication Server Administrator . . .
Enterprise Replication Terminology . . . . . .
Enterprise Replication Server . . . . . .
Replicate. . . . . . . . . . . . . .
Participant . . . . . . . . . . . . .
Replicate Set . . . . . . . . . . . .
Global Catalog . . . . . . . . . . .
Enterprise Replication Considerations . . .
Operational Considerations . . . . . . .
Backup and Restore Considerations . . . .
Database and Table Design Considerations . .
Transaction Processing Considerations . . .
Replication Environment Considerations . .
Enterprise Replication Data Types . . . . .
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Section II
Setting Up and Managing Enterprise Replication
Chapter 3
Selecting the Enterprise Replication System and Network Topology
In This Chapter . . . . . . . . . .
Selecting the Enterprise Replication System
Primary-Target Replication System . .
Update-Anywhere Replication System .
Conflict Resolution . . . . . . .
Choosing a Replication Network Topology .
Fully Connected Topology . . . . .
Hierarchical Replication Topologies . .
Chapter 4
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Preparing the Replication Environment
In This Chapter . . . . . . . . . . . . .
Preparing the Network Environment . . . . . .
Setting Up the Hosts File . . . . . . . .
Setting Up the Services File. . . . . . . .
Setting Up the Trusted Environment . . . .
Verifying SQLHOSTS . . . . . . . . . .
Testing the Network Environment . . . . .
Preparing the Disk . . . . . . . . . . . .
Planning for Disk Space Requirements . . . .
Setting Up Send and Receive Queue Spool Areas
Setting Up the Grouper Paging File . . . . .
Creating ATS and RIS Directories . . . . .
Preparing the Database Server Environment . . .
Setting Environment Variables . . . . . .
Setting Configuration Parameters . . . . .
Preparing Data for Replication . . . . . . . .
Preparing Consistent Data . . . . . . . .
Blocking Replication . . . . . . . . . .
Preparing to Replicate User-Defined Types . .
Preparing to Replicate User-Defined Routines .
Preparing Tables for Conflict Resolution . . .
Preparing Logging Databases . . . . . . .
Loading and Unloading Data . . . . . . . .
Data Preparation Example . . . . . . . . .
Table of Contents v
Chapter 5
Using High-Availability Data Replication with Enterprise
Replication
In This Chapter . . . . . . . . . . . . . . . . . .
High-Availability Replication System . . . . . . . . . .
Using HDR in a Hierarchical Tree Topology . . . . . .
Using HDR in a Forest of Trees Topology . . . . . . .
Preparing HDR Database Servers . . . . . . . . . . .
HDR Requirements . . . . . . . . . . . . . . .
Setting Up Database Server Groups . . . . . . . . .
Preparing to Replicate UDTs, UDRs, and DataBlade Modules
Loading and Unload Data. . . . . . . . . . . . .
Managing Enterprise Replication with High-Availability
Data Replication . . . . . . . . . . . . . .
Row Data Sbspace Logging . . . . . . . . . . . .
HDR Failure . . . . . . . . . . . . . . . . .
Performance Considerations . . . . . . . . . . . .
Chapter 6
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Defining and Modifying Replication Servers, Replicates, and
Participants
In This Chapter . . . . . . . . . . . . . .
Initializing Database Servers . . . . . . . . .
Defining Replication Servers . . . . . . . . .
Customizing the Replication Server Definition .
Defining Replicates . . . . . . . . . . . .
Defining Participants . . . . . . . . . .
Specifying Conflict Resolution Rules and Scope .
Specifying Replication Frequency . . . . . .
Setting Up Error Logging . . . . . . . . .
Replicating Only Changed Columns . . . . .
Using the IEEE Floating Point or Canonical Format
Enabling Triggers . . . . . . . . . . .
Modifying Replication Servers . . . . . . . .
Modifying Replicates . . . . . . . . . . . .
Adding or Deleting Participants . . . . . .
Changing Replicate Attributes . . . . . . .
Resynchronizing Replication Servers . . . . . .
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Chapter 7
Managing Replication Servers and Replicates
In This Chapter . . . . . . . . . . . . .
Managing Replication Servers . . . . . . . .
Viewing Replication Server Attributes . . . .
Connecting to Another Replication Server . .
Stopping Replication on a Server . . . . . .
Restarting Replication on a Stopped Server . .
Suspending Replication for a Server. . . . .
Resuming a Suspended Replication Server . .
Deleting a Replication Server . . . . . . .
Managing Replicates . . . . . . . . . . .
Viewing Replicate Properties . . . . . . .
Starting a Replicate . . . . . . . . . .
Stopping a Replicate . . . . . . . . . .
Suspending a Replicate . . . . . . . . .
Resuming a Suspended Replicate . . . . .
Deleting a Replicate . . . . . . . . . .
Managing Replication Server Network Connections
Viewing Network Connection Status . . . .
Dropping the Network Connection . . . . .
Reestablishing the Network Connection . . .
Chapter 8
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Creating and Managing Replicate Sets
In This Chapter . . . . . . . . . . . . . . .
Creating Replicate Sets . . . . . . . . . . . . .
Exclusive Replicate Sets . . . . . . . . . . .
Non-Exclusive Replicate Sets . . . . . . . . .
Customizing the Replicate Set Definition . . . . .
Viewing Replicate Set Properties . . . . . . . . .
Managing Replicate Sets . . . . . . . . . . . .
Starting a Replicate Set . . . . . . . . . . .
Stopping a Replicate Set . . . . . . . . . . .
Suspending a Replicate Set . . . . . . . . . .
Resuming a Replicate Set . . . . . . . . . .
Deleting a Replicate Set . . . . . . . . . . .
Modifying Replicate Sets . . . . . . . . . . . .
Adding or Deleting Replicates From a Replicate Set .
Changing Replication Frequency For the Replicate Set
Table of Contents vii
Chapter 9
Monitoring and Troubleshooting Enterprise Replication
In This Chapter . . . . . . . . . . . . . . . . .
Aborted Transaction Spooling Files . . . . . . . . . .
Preparing to Use ATS . . . . . . . . . . . . .
About ATS Filenames . . . . . . . . . . . . .
About ATS File Information . . . . . . . . . . .
BYTE and TEXT Information in ATS Files . . . . . .
Changed Column Information in ATS Files . . . . . .
BLOB and CLOB Information in ATS Files . . . . . .
UDT Information in ATS Files . . . . . . . . . .
Row Information Spooling Files . . . . . . . . . . .
Preparing to Use RIS . . . . . . . . . . . . .
About RIS Filenames . . . . . . . . . . . . .
BYTE and TEXT Information in RIS Files . . . . . .
Changed Column Information in RIS Files . . . . . .
BLOB and CLOB Information in RIS Files . . . . . .
UDT Information in RIS Files . . . . . . . . . .
Preventing Memory Queues from Overflowing . . . . . .
Preventing DDRBLOCK Mode . . . . . . . . . .
Monitoring Disk Usage for Send and Receive Queue Spool
Increasing the Sizes of Storage Spaces . . . . . . .
Recovering when Storage Spaces Fill . . . . . . . .
Solving Common Configuration Problems . . . . . . .
Enterprise Replication Event Alarms . . . . . . . . .
viii IBM Informix Dynamic Server Enterprise Replication Guide
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Section III
Appendixes
Appendix A
Command-Line Utility Reference
Appendix B
Configuration Parameter and Environment Variable Reference
Appendix C
onstat Command Reference
Appendix D
SMI Table Reference
Appendix E
Replication Examples
Appendix F
SQLHOSTS Registry Key
Appendix G
Notices
Index
Table of Contents ix
Introduction
Introduction
In This Introduction
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About This Manual . . . . . . .
Types of Users . . . . . . .
Software Dependencies . . . .
Assumptions About Your Locale .
Demonstration Databases . . .
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New Features in Dynamic Server, Version 9.4 . . . . . . . .
Extensibility Enhancements . . . . . . . . . . . .
Functionality Improvements . . . . . . . . . . . .
Security Enhancements . . . . . . . . . . . . . .
Command-Line Changes . . . . . . . . . . . . .
Configuration Parameters and Environment Variable Changes
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Documentation Conventions . . . . . . .
Typographical Conventions . . . . . .
Icon Conventions . . . . . . . . . .
Comment Icons . . . . . . . . .
Feature, Product, and Platform Icons . .
Command-Line Conventions . . . . . .
How to Read a Command-Line Diagram
Sample-Code Conventions . . . . . . .
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Related Reading .
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Compliance with Industry Standards
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IBM Welcomes Your Comments .
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2
IBM Informix Dynamic Server Enterprise Replication Guide
In This Introduction
This introduction provides an overview of the information in this manual
and describes the conventions it uses.
About This Manual
This manual describes IBM Informix Enterprise Replication and the concepts
of data replication. This manual explains how to design your replication
system, as well as administer and manage data replication throughout your
enterprise.
This section discusses the intended audience and the associated software
products that you must have to use Enterprise Replication.
Types of Users
This manual is for database server administrators and assumes that you have
the following background:
■
A working knowledge of your computer, your operating system,
and the utilities that your operating system provides
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Some experience working with relational databases or exposure to
database concepts
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Some experience with database server administration, operatingsystem administration, and network administration
If you have limited experience with relational databases, SQL, or your
operating system, refer to your Getting Started Guide for a list of supplementary titles.
Introduction 3
Software Dependencies
Software Dependencies
To use Enterprise Replication, you must use IBM Informix Dynamic Server as
your database server. Check the release notes for specific version
compatibility.
This manual assumes that you are using Dynamic Server, Version 9.4,
as your database server.
Assumptions About Your Locale
IBM Informix products can support many languages, cultures, and code sets.
All the information related to character set, collation and representation of
numeric data, currency, date, and time is brought together in a single
environment, called a GLS (Global Language Support) locale.
The examples in this manual are written with the assumption that you are
using the default locale, en_us.8859-1. This locale supports U.S. English
format conventions for date, time, and currency. In addition, this locale
supports the ISO 8859-1 code set, which includes the ASCII code set plus
many 8-bit characters such as é, è, and ñ.
If you plan to use nondefault characters in your data or your SQL identifiers,
or if you want to conform to the nondefault collation rules of character data,
you need to specify the appropriate nondefault locale.
For instructions on how to specify a nondefault locale, additional syntax, and
other considerations related to GLS locales, see the IBM Informix GLS User’s
Guide.
4
IBM Informix Dynamic Server Enterprise Replication Guide
Demonstration Databases
Demonstration Databases
The DB-Access utility, which is provided with your IBM Informix database
server products, includes one or more of the following demonstration
databases:
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The stores_demo database illustrates a relational schema with information about a fictitious wholesale sporting-goods distributor.
Many examples in IBM Informix manuals are based on the
stores_demo database.
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The superstores_demo database illustrates an object-relational
schema. The superstores_demo database contains examples of
extended data types, type and table inheritance, and user-defined
routines. ♦
For information about how to create and populate the demonstration
databases, see the IBM Informix DB-Access User’s Guide. For descriptions of the
databases and their contents, see the IBM Informix Guide to SQL: Reference.
The scripts that you use to install the demonstration databases reside in the
$INFORMIXDIR/bin directory on UNIX platforms and in the
%INFORMIXDIR%\bin directory in Windows environments.
New Features in Dynamic Server, Version 9.4
This section describes new Enterprise Replication features. These features fall
into the following areas:
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Extensibility Enhancements
■
Functionality Improvements
■
Security Enhancements
■
Command-Line Changes
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Configuration Parameters and Environment Variable Changes
For a description of all new features, see the Getting Started Guide.
Introduction 5
Extensibility Enhancements
Extensibility Enhancements
Enterprise Replication in Version 9.4 of Dynamic Server adds support for
replicating the following extended data types:
■
Row data types
■
Collection data types:
❑
Lists
❑
Sets
❑
Multisets
For information on which user-defined types are not supported, see the
release notes.
Functionality Improvements
Enterprise Replication for Dynamic Server, Version 9.4, includes the
following functionality enhancements:
■
Faster queue recovery
The addition of a table with replicate information to the transaction
records and row data tables reduces transaction processing time.
■
Replication during queue recovery
Users can connect to a database server during queue recovery; transactions are added to the queue. However, if the volume of
transactions during queue recovery is so large that the logical log is
in danger of being overwritten, replication is blocked.
■
Large transactions support
Enterprise Replication automatically spools large transactions to
disk instead of holding them in memory. Rows from spooled transactions are paged in and out of memory as needed. Enterprise
Replication can replicate transactions up to 4 TB in size.
6
IBM Informix Dynamic Server Enterprise Replication Guide
Security Enhancements
■
Improved availability
You can use High-Availability Data Replication (HDR) on critical
database servers in an Enterprise Replication system to provide
identical backup database servers.
■
Dynamic log file
Enterprise Replication can request the database server to add a new
dynamic log file if replication enters DDRBLOCK mode.
For more information, see “Preventing DDRBLOCK Mode” on
page 9-14.
Security Enhancements
Enterprise Replication supports the same levels of network encryption
available for client/server communications. Encryption is implemented in
Enterprise Replication with configuration parameters. For more information,
see for “Network Encryption” on page 1-8 for an overview of encryption.
Encryption configuration parameters are documented in Appendix B,
“Configuration Parameter and Environment Variable Reference.”
Command-Line Changes
This release includes the following updates to the command-line interface:
■
A new brief option for the cdr list replicate command to display a
summary of participants for all replicates.
■
The cdr remove command to remove Enterprise Replication from an
HDR server.
For more information, see Appendix A, “Command-Line Utility Reference.”
Configuration Parameters and Environment Variable
Changes
The CDR_QDATA_SBSPACE configuration parameter can now accept up to 32
sbspace names.
The CDR_QDATA_SBFLAGS configuration parameter is no longer supported.
Introduction 7
Configuration Parameters and Environment Variable Changes
This release includes the following new configuration parameters:
■
CDR_DBSPACE to specify the dbspace of the syscdr table
■
CDR_ENV to set Enterprise Replication environment variables
■
ENCRYPT_CDR to enable and set the level of network encryption
■
ENCRYPT_CIPHER to specify the ciphers to use for encryption
■
ENCRYPT_MAC to specify the level of message authentication coding
to use
■
ENCRYPT_MACFILE to specify MAC key files
■
ENCRYPT_SWITCH to define the frequency at which ciphers and
secret keys are renegotiated
This release includes the following new environment variables:
■
CDR_LOGDELTA to determine when the send and receive queues are
spooled to disk
■
CDR_PERFLOG to enable queue tracing
■
CDR_ROUTER to disables intermediate acknowledgements of transactions in hierarchical topologies
■
CDR_RMSCALEFACT to set the number of DataSync threads started
for each CPU VP
For more information, see Appendix B, “Configuration Parameter and
Environment Variable Reference.”
8
IBM Informix Dynamic Server Enterprise Replication Guide
Documentation Conventions
Documentation Conventions
This section describes the conventions that this manual uses. These
conventions make it easier to gather information from this and other volumes
in the documentation set.
Typographical Conventions
This manual uses the following conventions to introduce new terms,
illustrate screen displays, describe command syntax, and so forth.
Convention
Meaning
KEYWORD
All primary elements in a programming language statement
(keywords) appear in uppercase letters in a serif font.
italics
italics
Within text, new terms and emphasized words appear in italics.
Within syntax and code examples, variable values that you are
to specify appear in italics.
italics
boldface
boldface
Names of program entities (such as classes, events, and tables),
environment variables, file and pathnames, and interface
elements (such as icons, menu items, and buttons) appear in
boldface.
monospace
monospace
Information that the product displays and information that you
enter appear in a monospace typeface.
KEYSTROKE
Keys that you are to press appear in uppercase letters in a sans
serif font.
♦
This symbol indicates the end of one or more product- or
platform-specific paragraphs.
➞
This symbol indicates a menu item. For example, “Choose
Tools➞Options” means choose the Options item from the
Tools menu.
Tip: When you are instructed to “enter” characters or to “execute” a command,
immediately press RETURN after the entry. When you are instructed to “type” the
text or to “press” other keys, no RETURN is required.
Introduction 9
Icon Conventions
Icon Conventions
Throughout the documentation, you will find text that is identified by several
different types of icons. This section describes these icons.
Comment Icons
Comment icons identify three types of information, as the following table
describes. This information always appears in italics.
Icon
Label
Description
Warning:
Identifies paragraphs that contain vital instructions,
cautions, or critical information
Important:
Identifies paragraphs that contain significant
information about the feature or operation that is
being described
Tip:
Identifies paragraphs that offer additional details or
shortcuts for the functionality that is being described
Feature, Product, and Platform Icons
Feature, product, and platform icons identify paragraphs that contain
feature-specific, product-specific, or platform-specific information.
Icon
Description
GLS
Identifies information that relates to the IBM Informix
Global Language Support (GLS) feature
UNIX
Identifies information that is specific to UNIX operating
system
Windows
Identifies information that is specific to the Windows
environments
10 IBM Informix Dynamic Server Enterprise Replication Guide
Command-Line Conventions
These icons can apply to an entire section or to one or more paragraphs
within a section. If an icon appears next to a section heading, the information
that applies ends at the next heading at the same or higher level. A ♦ symbol
indicates the end of information that appears in one or more paragraphs
within a section.
Command-Line Conventions
This section defines and illustrates the format of commands that are available
in IBM Informix products. These commands have their own conventions,
which might include alternative forms of a command, required and optional
parts of the command, and so forth.
Each diagram displays the sequences of required and optional elements that
are valid in a command. A diagram begins at the upper-left corner with a
command. It ends at the upper-right corner with a vertical line. Between
these points, you can trace any path that does not stop or back up. Each path
describes a valid form of the command. You must supply a value for words
that are in italics.
You might encounter one or more of the following elements on a commandline path.
Element
Description
command
This required element is usually the product name or
other short word that invokes the product or calls the
compiler or preprocessor script for a compiled
IBM Informix product. It might appear alone or precede
one or more options. You must spell a command exactly
as shown and use lowercase letters.
variable
A word in italics represents a value that you must
supply, such as a database, file, or program name. A table
following the diagram explains the value.
-flag
A flag is usually an abbreviation for a function, menu, or
option name, or for a compiler or preprocessor
argument. You must enter a flag exactly as shown,
including the preceding hyphen.
(1 of 2)
Introduction 11
Command-Line Conventions
Element
Description
.ext
A filename extension, such as .sql or .cob, might follow
a variable that represents a filename. Type this extension
exactly as shown, immediately after the name of the file.
The extension might be optional in certain products.
(.,;+*-/)
Punctuation and mathematical notations are literal
symbols that you must enter exactly as shown.
' '
Single quotes are literal symbols that you must enter as
shown.
A reference in a box represents a subdiagram. Imagine
that the subdiagram is spliced into the main diagram at
this point. When a page number is not specified, the
subdiagram appears on the same page.
Privileges
p. 5-17
Privileges
A shaded option is the default action.
ALL
Syntax within a pair of arrows indicates a subdiagram.
The vertical line terminates the command.
-f
OFF
ON
,
variable
,
3
size
A branch below the main path indicates an optional
path. (Any term on the main path is required, unless a
branch can circumvent it.)
A loop indicates a path that you can repeat. Punctuation
along the top of the loop indicates the separator symbol
for list items.
A gate ( 3 ) on a path indicates that you can only use
that path the indicated number of times, even if it is part
of a larger loop. You can specify size no more than three
times within this statement segment.
(2 of 2)
12 IBM Informix Dynamic Server Enterprise Replication Guide
Sample-Code Conventions
How to Read a Command-Line Diagram
Figure 1 shows a command-line diagram that uses some of the elements that
are listed in the previous table.
Figure 1
Example of a Command-Line Diagram
setenv
INFORMIXC
compiler
pathname
To construct a command correctly, start at the top left with the command.
Follow the diagram to the right, including the elements that you want. The
elements in the diagram are case sensitive.
Figure 1 illustrates the following steps:
1.
Type setenv.
2.
Type INFORMIXC.
3.
Supply either a compiler name or a pathname.
After you choose compiler or pathname, you come to the terminator.
Your command is complete.
4.
Press RETURN to execute the command.
Sample-Code Conventions
Examples of SQL code occur throughout this manual. Except where noted,
the code is not specific to any single IBM Informix application development
tool. If only SQL statements are listed in the example, they are not delimited
by semicolons. For instance, you might see the code in the following example:
CONNECT TO stores_demo
...
DELETE FROM customer
WHERE customer_num = 121
...
COMMIT WORK
DISCONNECT CURRENT
Introduction 13
Additional Documentation
To use this SQL code for a specific product, you must apply the syntax rules
for that product. For example, if you are using DB-Access, you must delimit
multiple statements with semicolons. If you are using an SQL API, you must
use EXEC SQL at the start of each statement and a semicolon (or other appropriate delimiter) at the end of the statement.
Tip: Ellipsis points in a code example indicate that more code would be added in a
full application, but it is not necessary to show it to describe the concept being
discussed.
For detailed directions on using SQL statements for a particular application
development tool or SQL API, see the manual for your product.
Additional Documentation
IBM Informix Dynamic Server documentation is provided in a variety of
formats:
■
Online manuals. The documentation CD in your media pack allows
you to print the product documentation. You can obtain the same
online manuals at the IBM Informix Online Documentation site at
http://www-3.ibm.com/software/data/informix/pubs/library/.
■
Online help. This facility provides context-sensitive help, an error
message reference, language syntax, and more.
■
Documentation notes and release notes. Documentation notes,
which contain additions and corrections to the manuals, and release
notes are located in the directory where the product is installed.
Please examine these files because they contain vital information
about application and performance issues.
14 IBM Informix Dynamic Server Enterprise Replication Guide
Additional Documentation
On UNIX platforms, the following online files appear in the
$INFORMIXDIR/release/en_us/0333 directory.
UNIX
Online File
Purpose
ids_erep_docnotes_9.40.html
The documentation notes file
describes features that are not
covered in the manual or that were
modified since publication.
ids_unix_release_notes_9.40.html,
The release notes file describes
feature differences from earlier
versions of IBM Informix products
and how these differences might
affect current products. This file also
contains information about any
known problems and their
workarounds.
ids_unix_release_notes_9.40.txt
ids_machine_notes_9.40.txt
The machine notes file describes
any special actions that you must
take to configure and use
IBM Informix products on your
computer. Machine notes are named
for the product described.
♦
Introduction 15
Related Reading
The following items appear in the Informix folder. To display this
folder, choose Start➞Programs➞Informix➞ Documentation Notes
or Release Notes from the task bar.
Windows
Program Group Item
Description
Documentation Notes
This item includes additions or corrections to
manuals with information about features that
might not be covered in the manuals or that
have been modified since publication.
Release Notes
This item describes feature differences from
earlier versions of IBM Informix products and
how these differences might affect current
products. This file also contains information
about any known problems and their
workarounds.
Machine notes do not apply to Windows platforms. ♦
■
IBM Informix software products provide ASCII files that contain all of
the error messages and their corrective actions. For a detailed
description of these error messages, refer to IBM Informix Error
Messages in the IBM Informix Online Documentation site at
http://www-3.ibm.com/software/data/informix/pubs/library/.
UNIX
Windows
To read the error messages on UNIX, you can use the finderr command to display the error messages online. ♦
To read error messages and corrective actions on Windows NT, use
the Informix Error Messages utility. To display this utility, choose
Start➞Programs➞Informix from the taskbar. ♦
Related Reading
For a list of publications that provide an introduction to database servers and
operating-system platforms, refer to your Getting Started Guide.
16 IBM Informix Dynamic Server Enterprise Replication Guide
Compliance with Industry Standards
Compliance with Industry Standards
The American National Standards Institute (ANSI) has established a set of
industry standards for SQL. IBM Informix SQL-based products are fully
compliant with SQL-92 Entry Level (published as ANSI X3.135-1992), which is
identical to ISO 9075:1992. In addition, many features of Informix database
servers comply with the SQL-92 Intermediate and Full Level and X/Open
SQL CAE (common applications environment) standards.
IBM Welcomes Your Comments
To help us with future versions of our manuals, let us know about any corrections or clarifications that you would find useful. Include the following
information:
■
The name and version of your manual
■
Any comments that you have about the manual
■
Your name, address, and phone number
Send electronic mail to us at the following address:
[email protected]
This address is reserved for reporting errors and omissions in our documentation. For immediate help with a technical problem, contact Customer
Services.
Introduction 17
Chapter 1
About IBM Informix Enterprise Replication
Chapter 2
Overview of Enterprise Replication Administration
Section I
Introducing Enterprise
Replication
Chapter
About IBM Informix Enterprise
Replication
In This Chapter .
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IBM Informix Enterprise Replication .
Asynchronous Data Replication .
Log-Based Data Capture . . .
High Performance . . . . . .
High Availability . . . . . .
Consistent Information Delivery .
Flexible Architecture . . . . .
Centralized Administration . .
Network Encryption . . . . .
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1-13
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1-18
1-18
How Enterprise Replication Replicates Data . . .
Capturing Transactions . . . . . . . . .
Evaluating Data for Replication . . . . . .
Row Images . . . . . . . . . . .
Evaluating Rows for Updates . . . . .
Send Data Queues and Receive Data Queues
Data Evaluation Examples . . . . . .
Distributing Data . . . . . . . . . . .
Applying Replicated Data . . . . . . . .
1-2
IBM Informix Dynamic Server Enterprise Replication Guide
In This Chapter
Data replication generates and manages multiple copies of data at one or
more sites, which allows an enterprise to share corporate data throughout its
organization.
This chapter introduces IBM Informix Enterprise Replication and explains
how this product replicates data.
IBM Informix Enterprise Replication
IBM Informix Enterprise Replication is an asynchronous, log-based tool for
replicating data between IBM Informix Dynamic Server database servers.
Enterprise Replication on the source server captures transactions to be replicated by reading the logical log, storing the transactions, and reliably
transmitting each transaction as replication data to the target servers.
At each target server, Enterprise Replication receives and applies each transaction contained in the replication data to the appropriate databases and
tables as a normal, logged transaction.
IBM Informix Enterprise Replication provides the following:
■
Asynchronous Data Replication
■
Log-Based Data Capture
■
High Performance
■
High Availability
■
Consistent Information Delivery
■
Flexible Architecture
About IBM Informix Enterprise Replication 1-3
Asynchronous Data Replication
■
Centralized Administration
■
Network Encryption
Asynchronous Data Replication
Enterprise Replication uses asynchronous data replication to update the
databases that reside at a replicated site after the primary database has
committed a change.
With asynchronous replication, the delay to update the replicated-site
databases can vary depending on the business application and user requirements. However, the data eventually synchronizes to the same value at all
sites. The major benefit of this type of data replication is that if a particular
database server fails, the replication process can continue and all transactions
in the replication system will be committed.
In contrast with synchronous data replication, the data is replicated immediately when the source data is updated. Synchronous data replication uses the
two-phase commit technology to protect data integrity. In a two-phase commit,
a transaction is applied only if all interconnected distributed sites agree to
accept the transaction. Synchronous data replication is appropriate for applications that require immediate data synchronization. However, synchronous
data replication requires that all hardware components and networks in the
replication system be available at all times. For more information about
synchronous replication, refer to the discussion of two-phase commit in your
IBM Informix Dynamic Server Administrator’s Guide.
Asynchronous replication is often preferred because it allows for system and
network failures.
Asynchronous replication allows the following replication models:
■
Primary-target (“Primary-Target Replication System” on page 3-3)
All database changes originate at the primary database and are
replicated to the target databases. Changes at the target databases are
not replicated to the primary.
■
Update-anywhere (“Update-Anywhere Replication System” on
page 3-8)
All databases have read and write capabilities. Updates are applied
at all databases.
1-4
IBM Informix Dynamic Server Enterprise Replication Guide
Log-Based Data Capture
The update-anywhere model provides the greater challenge in asynchronous
replication. For example, if a replication system contains three replication
sites that all have read and write capabilities, conflicts occur when the sites
try to update the same data at the same time. Conflicts must be detected and
resolved so that the data elements eventually have the same value at every
site. For more information, see “Conflict Resolution” on page 3-10.
Log-Based Data Capture
Enterprise Replication uses log-based data capture to gather data for replication. Enterprise Replication reads the logical log to obtain the row images
for tables that participate in replication and then evaluates the row images.
Log-based data capture takes changes from the logical log and does not
compete with transactions for access to production tables. Log-based datacapture systems operate as part of the normal database-logging process and
thus add minimal overhead to the system.
Two additional methods of data capture, which Enterprise Replication does
not support, include:
■
Trigger-based data capture
A trigger is code in the database that is associated with a piece of
data. When the data changes, the trigger activates the replication
process.
■
Trigger-based transaction capture
A trigger is associated with a table. Data changes are grouped into
transactions and a single transaction might trigger several replications if it modifies several tables. The trigger receives the whole
transaction, but the procedure that captures the data runs as a part of
the original transaction, thus slowing down the original transaction.
About IBM Informix Enterprise Replication 1-5
High Performance
High Performance
Enterprise Replication provides high performance by not overly burdening
the source of the data and by using networks and all other resources
efficiently.
Because Enterprise Replication captures changes from the logical log instead
of competing with transactions that access production tables, Enterprise
Replication minimizes the effect on transaction performance. Because the
capture mechanism is internal to the database, the database server
implements this capture mechanism efficiently. For more information, see
“Log-Based Data Capture” on page 1-5.
All Enterprise Replication operations are performed in parallel, which
further extends the performance of Enterprise Replication. For more information, see “Functionality Improvements” on page 6 of the Introduction.
High Availability
Because Enterprise Replication implements asynchronous data replication,
network and target database server outages are tolerated. In the event of a
database server or network failure, the local database server continues to
service local users. The local database server stores replicated transactions in
persistent storage until the remote server becomes available.
If high availability is critical, you can use High-Availability Data Replication
(HDR) in conjunction with Enterprise Replication. HDR supports
synchronous data replication between two database servers: a primary
server, which can participate in Enterprise Replication, and a secondary
server, which is read-only and does not participate in Enterprise Replication.
If a primary server in an HDR pair fails, you switch the secondary server to
the standard server, allowing it to participate in Enterprise Replication.
Client connections to the original primary server can be automatically
switched to the new standard server.
For more information on using HDR with Enterprise Replication, see “Using
High-Availability Data Replication with Enterprise Replication.”
1-6
IBM Informix Dynamic Server Enterprise Replication Guide
Consistent Information Delivery
Consistent Information Delivery
Enterprise Replication protects data integrity. All Enterprise Replication
transactions are stored in a reliable queue to maintain the consistency of
transactions.
Enterprise Replication uses a data-synchronization process to ensure that
transactions are applied at the target database servers in any order equivalent
to the order that they were committed on the source database server. If Enterprise Replication can preserve the consistency of the database, Enterprise
Replication might commit transactions in a slightly different order on the
target database.
If update conflicts occur, Enterprise Replication provides built-in automatic
conflict detection and resolution. You can configure the way conflict
resolution behaves to meet the needs of your enterprise. For more information, see “Conflict Resolution” on page 3-10.
Flexible Architecture
Enterprise Replication allows replications based on specific business and
application requirements and does not impose model or methodology
restrictions on the enterprise.
Enterprise Replication supports both primary-target and update-anywhere
replication models. For more information, see “Selecting the Enterprise
Replication System” on page 3-3.
Enterprise Replication supports the following network topologies:
■
Fully connected
Continuous connectivity between all participating database servers.
■
Hierarchical tree
A parent-child configuration that supports continuous and intermittent connectivity.
■
Forest of trees
Multiple hierarchical trees that connect at the root database servers.
About IBM Informix Enterprise Replication 1-7
Centralized Administration
You can add High-Availability Data Replication to any of these topologies.
For more information on topologies, see “Choosing a Replication Network
Topology” on page 3-18.
Enterprise Replication supports all built-in Informix data types, as well as
extended and user-defined data types. For more information, see “Enterprise
Replication Data Types” on page 2-19.
Enterprise Replication operates in a LAN, WAN, and combined LAN/WAN
configuration across a range of network transport protocols.
Enterprise Replication supports the Global Language Support (GLS) feature,
which allows IBM Informix products to handle different languages, regional
conventions, and code sets. For more information, see “Using GLS with
Enterprise Replication” on page 2-18.
Centralized Administration
Enterprise Replication allows administrators to easily manage all the
distributed components of the replication system from a single point of
control.
You can use the command-line utility (CLU) to administer the replication
system from your system command prompt and connect to other servers
involved in replication, as necessary. For information, see Appendix A,
“Command-Line Utility Reference.”
In addition, you can use IBM Informix Server Administrator (ISA) to administer your replication system from a web browser. For more information, see
the Documentation Notes described in “Additional Documentation” on
page 14 of the Introduction.
Network Encryption
Enterprise Replication supports the same network encryption that you can
use with client/server communications to provide complete data encryption
with the OpenSSL library. A message authentication code (MAC) is transmitted as part of the encrypted data transmission to ensure data integrity. A
MAC is an encrypted message digest. The encryption algorithms use
OpenSSL 0.9.6 as the code base.
1-8
IBM Informix Dynamic Server Enterprise Replication Guide
How Enterprise Replication Replicates Data
However, encryption is implemented differently for Enterprise Replication
than for client/server communications:
■
Client/server network encryption uses the ENCCSM communications support module (CSM) that is specified in the SQLHOSTS file.
■
Enterprise Replication encryption requires setting encryption configuration parameters.
Enterprise Replication cannot accept a connection that is configured with a
CSM. To combine client/server network encryption with Enterprise Replication encryption, configure two network connections for each database
server, one with CSM and one without. For more information, see “Network
Encryption and SQLHOSTS” on page 4-8.
Important: HDR does not support encryption. If you combine Enterprise Replication
with HDR, communication between Enterprise Replication servers and the HDR
primary server can be encrypted, but the communication between the HDR primary
server and the HDR secondary server cannot be encrypted.
Enterprise Replication encryption configuration parameters are documented
in Appendix B, “Configuration Parameter and Environment Variable
Reference.”
How Enterprise Replication Replicates Data
Before you can replicate data, you must declare a database server for replication and define the replicates (the data to replicate and the database servers
that participate in replication). To declare a database server for replication,
see “Defining Replication Servers” on page 6-5. To define replicates, see
“Defining Replicates” on page 6-7. Appendix E, “Replication Examples,” has
simple examples of declaring replication servers and defining replicates.
After the servers and replicates are defined, Enterprise Replication uses the
following steps to replicate data:
1.
Capturing Transactions
2.
Evaluating Data for Replication
3.
Distributing Data
4.
Applying Replicated Data
About IBM Informix Enterprise Replication 1-9
Capturing Transactions
Capturing Transactions
As the database server writes rows to the logical log, it marks rows that
should be replicated. Later, Enterprise Replication reads the logical log to
obtain the row images for tables that participate in replication.
Informix database servers manage the logical log in a circular fashion; the
most recent logical-log entries write over the oldest entries. Enterprise Replication must read the logical log quickly enough to prevent new logical-log
entries from overwriting the logs Enterprise Replication has not yet
processed. If the database server comes close to overwriting a logical log that
Enterprise Replication has not yet processed, user transactions are blocked
until Enterprise Replication can advance. (This situation is called DDRBLOCK
mode and occurs only if the system is severely misconfigured.)
The row images that participate in replication are passed to Enterprise Replication for further evaluation.
Evaluating Data for Replication
Enterprise Replication evaluates transactions based on a change to a final
image of a row.
Row Images
Enterprise Replication evaluates the initial and final images of a row and any
changes that occur between the two row images to determine which rows to
replicate. Each row image contains the data in the row as well as the action
performed on that row.
A row might change more than once in a particular transaction. For example,
a transaction might insert and then update a row prior to committing. Enterprise Replication evaluates the net effect (final state) of a transaction based on
the row buffers in the log. Enterprise Replication then determines what
should replicate, based on the net effect, the initial state of the row, and
whether the replicate definition (in particular, the WHERE clause) applies to
the initial and final state.
The table in Figure 1-1 shows the logic that determines which rows are candidates for replication.
1-10
IBM Informix Dynamic Server Enterprise Replication Guide
Evaluating Data for Replication
Figure 1-1
Enterprise Replication Evaluation Logic
Initial
Image
Replicate
Evaluates
Final
Image
Replicate
Evaluates
Primary-Key
Changed?
Send to Destination
Database Server
Comments
INSERT
T or F
DELETE
T or F
Yes or no
Nothing
Net change of transaction results in no
replication
INSERT
T or F
UPDATE
T
Yes or no
INSERT with final
row image
Inserts final data of
transaction
INSERT
T or F
UPDATE
F
Yes or no
Nothing
Final evaluation
determines no
replication
UPDATE
T
DELETE
T or F
Yes or no
DELETE with initial
row image
Net result of transaction is delete
UPDATE
F
DELETE
T or F
Yes or no
Nothing
Net change of transaction results in no
replication
UPDATE
T
UPDATE
T
Yes
DELETE with initial
row image and
INSERT with final
row image
Ensures old primary
key does not
replicate
UPDATE
T
UPDATE
T
No
UPDATE with final
row image
Simple update
UPDATE
T
UPDATE
F
Yes or no
DELETE with initial
row image
Row no longer
matches replicate
definition
UPDATE
F
UPDATE
T
Yes or no
INSERT with final
row image
Row now matches
replicate definition
UPDATE
F
UPDATE
F
Yes or no
Nothing
No match exists, and
therefore, no
replication
About IBM Informix Enterprise Replication 1-11
Evaluating Data for Replication
Where:
■
Initial image is the before image of the transaction in the logical log.
■
The replicate evaluates to T (true) or F (false).
■
Final image is the image of the transaction that is replicated.
The table in Figure 1-1 on page 1-11 illustrates how Enterprise Replication
evaluates the row-image type (INSERT, UPDATE, DELETE), the results of
evaluating the replicate WHERE clause for both the initial and final image,
and whether the primary key changes as a result of the transaction.
Tip: The evaluation logic in Figure 1-1 on page 1-11 assumes that the source and the
destination tables are initially synchronized (identical before replication begins). If
the tables were not synchronized, anomalous behavior could result.
After Enterprise Replication identifies transactions that qualify for replication, Enterprise Replication transfers the transaction data to a queue.
1-12
IBM Informix Dynamic Server Enterprise Replication Guide
Evaluating Data for Replication
Evaluating Rows for Updates
Enterprise Replication evaluates rows for primary-key updates, for WHEREclause column updates, and for multiple updates to the same row. The
following list describes an occurrence in a transaction and the Enterprise
Replication action:
■
Primary-key updates
Enterprise Replication translates an update of a primary key into a
delete of the original row and an insert of the row image with the
new primary key. If triggers are enabled on the target system, insert
triggers are executed.
■
WHERE-clause column updates
If a replicate includes a WHERE clause in its data selection, the
WHERE clause imposes selection criteria for rows in the replicated
table.
■
❑
If an update changes a row so that it no longer passes the
selection criteria on the source, it is deleted from the target table.
Enterprise Replication translates the update into a delete and
sends it to the target.
❑
If an update changes a row so that it passes the selection criteria
on the source, it is inserted into the target table. Enterprise Replication translates the update into an insert and sends it to the
target.
Multiple-row images in a transaction
Enterprise Replication compresses multiple-row images and only
sends the net change to the target. Because of this, triggers might not
execute on the target database. For more information, see “Triggers”
on page 2-13.
Enterprise Replication supports the replication of BYTE and TEXT data types
(simple large objects) and BLOB and CLOB data types (smart large objects),
and opaque user-defined data types, as well as all built-in Informix data
types. However, Enterprise Replication implements the replication of these
types of data somewhat differently from the replication of other data types.
For more information, see “Replicating Simple and Smart Large Objects” on
page 2-20, and “Replicating Opaque User-Defined Data Types” on page 2-25.
About IBM Informix Enterprise Replication 1-13
Evaluating Data for Replication
Send Data Queues and Receive Data Queues
Enterprise Replication uses send and receive queues to receive and deliver
replication data to and from database servers that participate in a replicate:
■
Send queue
Enterprise Replication stores replication data in memory to be
delivered to target database servers that participate in a replicate. If
the send queue fills, Enterprise Replication spools the send queue
transaction records to a dbspace and the send queue row data to an
sbspace.
■
Receive queue
Enterprise Replication stores replication data in memory at the target
database server until the target database server acknowledges
receipt of the data. If the receive queue fills as a result of a large transaction, Enterprise Replication spools the receive queue transaction
header and replicate records to a dbspace and the receive queue row
data to an sbspace. For more information, see“Large Transactions”
on page 2-15.
For more information, see “Setting Up Send and Receive Queue Spool Areas”
on page 4-12 and “Preventing Memory Queues from Overflowing” on
page 9-12.
The data contains the filtered log records for a single transaction. Enterprise
Replication stores the replication data in a stable (recoverable) send queue on
the source database server. Target sites acknowledge receipt of data when it
is applied to or rejected from the target database.
If a target database server is unreachable, the replication data remains in a
stable queue at the source database server. Temporary failures are common
and no immediate action is taken by the source database server; it continues
to queue transactions. When the target database server becomes available
again, queued transactions are transmitted and applied (see “Applying
Replicated Data” on page 1-18).
1-14
IBM Informix Dynamic Server Enterprise Replication Guide
Evaluating Data for Replication
If the target database server is unavailable for an extended period, the send
queue on the source database server might consume excessive resources. In
this situation, you might not want to save all transactions for the target
database server. To prevent unlimited transaction accumulation, you can
remove the unavailable target database server from the replicate (see
“Managing Replication Servers” on page 7-3). Before the database server that
is removed rejoins any replicate, however, you must synchronize (bring
tables to consistency) with the other database servers (see “Resynchronizing
Replication Servers” on page 6-16).
Data Evaluation Examples
Figure 1-2, Figure 1-4 on page 1-16, and Figure 1-6 on page 1-17 show three
examples of how Enterprise Replication uses logic to evaluate transactions
for potential replication.
Replicate SQL=SELECT emp_id, salary FROM employee WHERE exempt = “N”;
dallas_office
phoenix_office
Figure 1-2
Insert Followed by a
Delete
BEGIN WORK;
INSERT INTO employee
VALUES (927, “Smith”...
DELETE FROM employee
WHERE emp_id=927
COMMIT WORK;
Figure 1-2 shows a transaction that takes place at the Dallas office. Enterprise
Replication uses the logic in Figure 1-3 to evaluate whether any information
is sent to the destination database server at the Phoenix office.
About IBM Informix Enterprise Replication 1-15
Evaluating Data for Replication
Figure 1-3
Insert Followed by a Delete Evaluation Logic
Initial Image
INSERT
Replicate
Evaluates
T or F
Final Image
DELETE
Replicate
Evaluates
T or F
Primary-Key
Changed?
Yes or no
Send to Destination
Database Server
Nothing
Enterprise Replication determines that the insert followed by a delete results
in no replication operation; therefore, no replication data is sent.
In Figure 1-4, Enterprise Replication uses the logic in Figure 1-5 to evaluate
whether any information is sent to the destination database server.
Replicate SQL=SELECT emp_id, salary FROM employee WHERE exempt = “N”;
dallas_office
BEGIN WORK;
phoenix_office
BEGIN WORK;
INSERT INTO employee
VALUES (927, "Smith", "N" ...
UPDATE employee
SET lname = "Jones"
WHERE emp_id = 927
COMMIT WORK;
1-16
IBM Informix Dynamic Server Enterprise Replication Guide
INSERT INTO employee
VALUES (927, "Jones" ...
COMMIT WORK;
Figure 1-4
Insert Followed by
an Update
Evaluating Data for Replication
Figure 1-5
Insert Followed by An Update Evaluation Logic
Replicate
Evaluates
Initial Image
INSERT
T or F
Replicate
Evaluates
Final Image
UPDATE
T
Primary-Key
Changed?
Send to Destination Database
Server
Yes or no
INSERT with final row
image
The replicate WHERE clause imposes the restriction that only rows with the
exempt column equal to “N” are replicated. Enterprise Replication evaluates
the transaction (an insert followed by an update) and converts it to an insert
to propagate the updated (final) image.
In Figure 1-6, Enterprise Replication uses the logic in Figure 1-7 to evaluate
whether any information is sent to the destination database server.
Replicate SQL=SELECT emp_id, salary FROM employee WHERE exempt = “N”;
phoenix_office
dallas_office
BEGIN WORK;
Figure 1-6
Update; Not
Selected to
Selected
BEGIN WORK;
INSERT INTO employee
VALUES (927, "Jones", ...
UPDATE employee
SET EXEMPT = "N"
WHERE emp_id = 927
COMMIT WORK;
COMMIT WORK;
Figure 1-7
Update; Not Selected to Selected Evaluation Logic
Replicate
Evaluates
Initial Image
UPDATE
F
Final Image
UPDATE
Replicate
Evaluates
T
Primary-Key
Changed?
Yes or no
Send to Destination Database
Server
INSERT with final row image
About IBM Informix Enterprise Replication 1-17
Distributing Data
The example shows a replicate WHERE clause column update. A row that
does not meet the WHERE clause selection criteria is updated to meet the
criteria. Enterprise Replication replicates the updated row image and
converts the update to an insert.
Distributing Data
Enterprise Replication ensures that all data reaches the appropriate server,
regardless of a network or system failure. In the event of a failure, Enterprise
Replication stores data until the network or system is operational. Enterprise
Replication replicates data efficiently with a minimum of data copying and
sending.
Applying Replicated Data
Enterprise Replication uses a data-synchronization process to apply the replicated data to target database servers. The target database servers
acknowledge receipt of data when the data is applied to the target database.
The data-synchronization process ensures that transactions are applied at the
target database servers in an order equivalent to the order that they were
committed on the source database server. If consistency can be preserved,
Enterprise Replication might commit transactions out of order on the target
database.
When Enterprise Replication applies replication data, it checks to make sure
that no collisions exist. A collision occurs when two database servers update
the same data simultaneously. Enterprise Replication reviews the data one
row at a time to detect a collision.
If Enterprise Replication finds a collision, it must resolve the conflict before
applying the replication data to the target database server.
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IBM Informix Dynamic Server Enterprise Replication Guide
Applying Replicated Data
Pakistan
Time= 12:29:25
Products (in inventory)
India
Column
...
field value
field value
field value
Pakistan
Bangkok
Figure 1-8
Collision Example
Column
field value
...
Bangkok
Time= 12:29:27
Figure 1-8 shows a situation that yields a conflict. Pakistan updates the row
two seconds before Bangkok updates the same row. The Bangkok update
arrives at the India site first, and the Pakistan update follows. The Pakistan
time is earlier than the Bangkok time. Because both updates involve the same
data and a time discrepancy exists, Enterprise Replication detects a collision.
For more information, see “Conflict Resolution” on page 3-10.
Enterprise Replication scans to see if the same primary key already exists in
the target table or in the associated delete table, or if a replication order error is
detected. A delete table stores the row images of deleted rows. A replication
order error is the result of replication data that arrives from different database
servers with one of the following illogical results:
■
A replicated DELETE that finds no row to DELETE on the target
■
An UPDATE that finds no row to UPDATE on the target
■
An INSERT that finds a row that already exists on the target
About IBM Informix Enterprise Replication 1-19
Chapter
Overview of Enterprise
Replication Administration
In This Chapter .
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2-3
Overview of Enterprise Replication Administration
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2-3
Enterprise Replication Server Administrator .
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2-4
Enterprise Replication Terminology . . . .
Enterprise Replication Server . . . . .
Replicate . . . . . . . . . . . .
Participant . . . . . . . . . . .
Replicate Set . . . . . . . . . . .
Global Catalog . . . . . . . . . .
Enterprise Replication Considerations . .
Operational Considerations . . . . .
Backup and Restore Considerations. . .
Database and Table Design Considerations
Unbuffered Logging. . . . . . .
Table Types . . . . . . . . . .
Out-of-Row Data . . . . . . . .
Shadow Columns. . . . . . . .
Primary Key Constraint . . . . .
SERIAL Data Types and Primary Keys
Cascading Deletes . . . . . . .
Triggers . . . . . . . . . . .
Sequence Objects . . . . . . . .
Transaction Processing Considerations. .
Replication Volume . . . . . . .
Distributed Transactions . . . . .
Large Transactions . . . . . . .
Supported SQL Statements . . . .
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2-5
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2-6
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2-6
2-8
2-8
2-9
2-9
2-10
2-10
2-11
2-11
2-11
2-12
2-12
2-13
2-14
2-14
2-14
2-14
2-15
2-15
Replication Environment Considerations . . .
Time Synchronization . . . . . . . .
Using GLS with Enterprise Replication . .
Enterprise Replication Data Types . . . . .
Replicating on Heterogeneous Hardware .
Replicating Simple and Smart Large Objects
Replicating Opaque User-Defined Data Types
2-2
IBM Informix Dynamic Server Enterprise Replication Guide
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2-17
2-17
2-18
2-19
2-19
2-20
2-25
In This Chapter
This chapter introduces you to Enterprise Replication administration and
describes the Enterprise Replication server administrator, Enterprise Replication terminology, and considerations for using Enterprise Replication.
Overview of Enterprise Replication Administration
To set up Enterprise Replication
1.
Select the Enterprise Replication system and network topology to
use for your replication environment.
For information, see Chapter 3, “Selecting the Enterprise Replication
System and Network Topology.”
2.
Prepare the replication environment.
For information, see Chapter 4, “Preparing the Replication
Environment.”
3.
Initialize the database server.
For information, see Chapter 6, “Defining and Modifying Replication Servers, Replicates, and Participants.”
4.
Define database servers for replication.
For information, see Chapter 6.
5.
Define replicates and participants.
For information, see Chapter 7, “Managing Replication Servers and
Replicates.”
Overview of Enterprise Replication Administration 2-3
Enterprise Replication Server Administrator
6.
Create replicate sets (optional).
For information, see Chapter 8, “Creating and Managing Replicate
Sets.”
7.
Start the replicate.
For information, see Chapter 7.
Once you configure Enterprise Replication, use this information to manage
your replication environment:
■
“Managing Replication Servers” on page 7-3
■
“Managing Replicates” on page 7-7
■
“Managing Replicate Sets” on page 8-6
■
“Monitoring and Troubleshooting Enterprise Replication” on
page 9-1
Enterprise Replication Server Administrator
The Enterprise Replication server administrator must have Informix administrator privileges to configure and manage Enterprise Replication.
2-4
Operating System
Privileges
UNIX
user informix
Windows
member of the Informix-Admin group
IBM Informix Dynamic Server Enterprise Replication Guide
Enterprise Replication Terminology
Enterprise Replication Terminology
The following terms define the data in an Enterprise Replication system and
how it is treated:
■
Enterprise Replication Server
■
Replicate
■
Participant
■
Replicate Set
■
Global Catalog
Enterprise Replication Server
An Enterprise Replication server, or replication server, is an Informix database
server that participates in data replication. The replication server maintains
information about the replication environment, which columns should be
replicated, and the conditions under which the data should be replicated.
This information is stored in a database, syscdr, that the database server
creates when it is initialized. Multiple database servers can be on the same
physical computer, and each database server can participate in Enterprise
Replication.
Important: For each server participating in replication, you must set up a database
server group in the SQLHOSTS file (UNIX) or registry (Windows). For more information, see “Setting up Database Server Groups” on page 4-5 and Appendix F,
“SQLHOSTS Registry Key.”
Tip: This manual uses the convention that the name of a database server group is g_
followed by the name of a database server that is in the group; for example, g_italy.
For more information, see “Defining Replication Servers” on page 6-5 and
“cdr define server” on page A-19.
Overview of Enterprise Replication Administration 2-5
Replicate
Replicate
A replicate defines the replication participants and various attributes of how to
replicate the data, such as frequency and how to handle any conflicts during
replication.
For more information, see “Defining Replicates” on page 6-7 and “cdr define
replicate” on page A-10.
Participant
A participant specifies the data (database, table, and columns) to replicate and
the database servers to which the data replicates.
Important: You cannot start and stop replicates that have no participants.
For more information, see “Defining Participants” on page 6-8 and “Participant” on page A-88.
Replicate Set
A replicate set combines several replicates to form a set that can be administered together as a unit.
If your replication system contains many replicates that you define as part of
a replicate set, you can use a single command to start, stop, suspend, or
resume all the replicates in the set.
For more information, see Chapter 8, “Creating and Managing Replicate
Sets” and “cdr change replicateset” on page A-6.
Global Catalog
Each database server that participates in Enterprise Replication maintains
tables in the syscdr database to keep track of Enterprise Replication configuration information and state. For all root and nonroot replication servers, this
catalog is a global catalog that maintains a global inventory of Enterprise
Replication configuration information. The global catalog is created when
you define the server for replication. For more information, see “Replication
Topology Terms” on page 3-20.
2-6
IBM Informix Dynamic Server Enterprise Replication Guide
Global Catalog
The global catalog includes the following:
■
Enterprise Replication server definitions and state
■
Routing and connectivity information
■
Replicate definitions and state
■
Participant definitions and state
■
Replicate set definitions and state
■
Conflict detection and resolution rules and any associated SPL
routines
The tables in one global catalog instance are automatically replicated to the
global catalogs of all other replication servers (except leaf servers), thus you
can manage the entire replication environment from one non-leaf replication
server. For information about managing replication servers (and their global
catalogs), refer to “Managing Replication Servers” on page 7-3.
Leaf replication servers (“Replication Topology Terms” on page 3-20) have a
limited catalog. Because the parent database server always manages operations that involve a leaf database server, the catalog of the leaf database
server contains only enough data to allow it to interact with its parent server.
Limiting the catalog of leaf database servers makes the replication system
more efficient because the global catalogs do not need to be replicated to the
leaf servers.
For information on defining root, nonroot, and leaf servers, see “Customizing
the Replication Server Definition” on page 6-6.
Overview of Enterprise Replication Administration 2-7
Enterprise Replication Considerations
Enterprise Replication Considerations
This section discusses items to consider when planning to use Enterprise
Replication:
■
Operational Considerations
■
Backup and Restore Considerations
■
Database and Table Design Considerations
■
Transaction Processing Considerations
■
Replication Environment Considerations
■
Enterprise Replication Data Types
Operational Considerations
Enterprise Replication imposes the following operational limitations:
■
Enterprise Replication supports replication on IBM Informix
Dynamic Server only.
■
Replication is restricted to base tables. That is, you cannot define a
replicate on a view or synonym. A view is a synthetic table, a
synthesis of data that exists in real tables and other views. A synonym
is an alternative name for a table or a view. For more information on
views and synonyms, see the IBM Informix Database Design and Implementation Guide.
■
Replication is not inherited by any child tables in a typed hierarchy.
Enterprise Replication asynchronously propagates many control operations
through the Enterprise Replication network. When you perform administrative functions using Enterprise Replication, the status that returns from
those operations is indicative only of the success or failure of the operation at
the database server to which you are directly connected. The operation might
still be propagating through the other Enterprise Replication database
servers in the network at that time.
2-8
IBM Informix Dynamic Server Enterprise Replication Guide
Backup and Restore Considerations
Due to this asynchronous propagation, avoid performing control operations
in quick succession that might directly conflict with one another without
verifying that the first operation has successfully propagated through the
entire enterprise network. Specifically, avoid deleting Enterprise Replication
objects such as replicates, replicate sets, and Enterprise Replication servers,
and immediately re-creating those objects with the same name. Doing so can
cause failures in the Enterprise Replication system at the time of the
operation or later. These failures might manifest themselves in ways that do
not directly indicate the source of the problem.
If you must delete and re-create a definition, use a different name for the new
object (for example, delete replicate a.001 and recreate it as a.002) or wait until
the delete action has successfully propagated through the entire Enterprise
Replication system before you re-create the object. The former strategy is
especially appropriate if you have database servers that are not connected to
the Enterprise Replication network at all times. It might take a significant
amount of time before the operation is propagated to those disconnected
servers.
Backup and Restore Considerations
When backing up and restoring database servers that participate in replication, do not stop Enterprise Replication before performing a backup on an
Enterprise Replication system.
Database and Table Design Considerations
Consider the following when designing databases and tables for replication:
■
Unbuffered Logging
■
Table Types
■
Shadow Columns
■
SERIAL Data Types and Primary Keys
■
Cascading Deletes
■
Triggers
■
Sequence Objects
Overview of Enterprise Replication Administration 2-9
Database and Table Design Considerations
Unbuffered Logging
Databases on all server instances involved in replication must be created with
logging.
It is recommended that you replicate tables only from databases created with
unbuffered logging. Enterprise Replication evaluates the logical log for transactions that modify tables defined for replication. If a table defined for
replication resides in a database that uses buffered logging, the transactions
are not immediately written to the logical log, but are instead buffered and
then written to the logical log in a block of logical records. When this occurs,
Enterprise Replication evaluates the buffer of logical-log records all at once,
which consumes excess CPU time and memory. When you define a table for
replication in a database created with unbuffered logging, Enterprise Replication can evaluate the transactions as they are produced.
To create a database with unbuffered logging, use:
CREATE DATABASE db_name WITH LOG
To minimize impact on the system, Enterprise Replication uses buffered
logging whenever possible, even if the database is defined as unbuffered. For
more information, see the section on CREATE DATABASE in the IBM Informix
Database Design and Implementation Guide.
Table Types
The following table types are not supported by Enterprise Replication:
■
RAW tables
Because RAW tables are not logged, they cannot be replicated using
Enterprise Replication.
■
Temporary tables
Because the database server deletes temporary tables when an application terminates or closes the database, you should not include
these tables in your replication environment.
For more information on table types, see IBM Informix Database Design and
Implementation Guide.
2-10
IBM Informix Dynamic Server Enterprise Replication Guide
Database and Table Design Considerations
Out-of-Row Data
Enterprise Replication collects out-of-row data for transmission after the user
transaction has committed. Due to activity on the replicated row, the data
might not exist at the time Enterprise Replication collects it for replication. In
such cases, Enterprise Replication normally applies a NULL on the target
system. Therefore, you should avoid placing a NOT NULL constraint on any
replicated column that includes out-of-row data.
Shadow Columns
In an update-anywhere replication environment, you must provide for
conflict resolution using a conflict-resolution rule (see “Conflict Resolution”
on page 3-10). When you create a table that uses the time stamp or time stamp
plus SPL conflict-resolution rule, you must define the shadow columns,
cdrserver and cdrtime on both the source and target replication servers.
Tip: If you plan to use only the ignore conflict-resolution rule, you do not need to
define the cdrserver and cdrtime shadow columns.
For more information, see “Preparing Tables for Conflict Resolution” on
page 4-25.
Primary Key Constraint
All tables involved in replication must have a PRIMARY KEY constraint
defined on at least one column, which forces the column to be unique. (For
more information about primary keys, see the IBM Informix Database Design
and Implementation Guide and the IBM Informix Guide to SQL: Syntax.)
Important: Because primary key updates are sent as DELETE/INSERT statement
pairs, avoid changing the primary key and updating data in the same transaction.
Overview of Enterprise Replication Administration 2-11
Database and Table Design Considerations
SERIAL Data Types and Primary Keys
If you plan to use SERIAL data types (SERIAL and SERIAL8) as the primary key
for a table, the same serial value might be generated on two servers at the
same time.
To avoid this problem, use the CDR_SERIAL configuration parameter to
generate non-overlapping (unique) values for SERIAL columns across all
database servers in your replication environment. Set CDR_SERIAL in the
ONCONFIG file for each primary (source) database server. For more information and examples, see “CDR_SERIAL Configuration Parameter” on
page B-14.
If you do not set CDR_SERIAL, you must specify that the serial column is part
of a composite primary key, to avoid generating non-unique SERIAL primary
keys. The non-serial column part of the primary key identifies the server on
which the row was initially created.
Cascading Deletes
If a table includes a cascading delete, when a parent row is deleted, the children
are also deleted. If both the parent and child tables participate in replication,
the deletes for both the parent and child are replicated to the target servers.
If the same table definition exists on the target database, Enterprise Replication attempts to delete the child rows twice. Enterprise Replication usually
processes deletes on the parent first and then the children. When Enterprise
Replication processes deletes on the children, an error might result, because
the rows were already deleted when the parent was deleted. The table in
Figure 2-1 indicates how Enterprise Replication resolves cascading deletes
with conflict-resolution scopes and rules.
For more information on cascading deletes, see the ON DELETE CASCADE
section in the IBM Informix Guide to SQL: Syntax.
2-12
IBM Informix Dynamic Server Enterprise Replication Guide
Database and Table Design Considerations
Figure 2-1
Resolving Cascade Deletes
Conflict-Resolution
Rule
Conflict-Resolution Scope
Actions on Delete Errors
Result
Time stamp
Row-by-row or transaction Note as replication
exceptions
Process children rows
Ignore
Transaction
Report as errors
Abort entire transaction
Ignore
Row-by-row
Report as errors
Reject row
Triggers
A trigger is a database object that automatically sets off a specified set of SQL
statements when a specified event occurs.
If the --firetrigger option is enabled on a replicate, any triggers defined on a
table that participates in replication are invoked when transactions are
processed on the target server. However, because Enterprise Replication only
replicates the final result of a transaction, triggers execute only once on the
target regardless of how many triggers executed on the source. In cases
where the final evaluation of the transaction results in no replication (for
example, an INSERT where the final row image is a DELETE, as shown in
Figure 1-3 on page 1-16), no triggers execute on the target database.
If the same triggers are defined on both the source and target tables, any
INSERT, UPDATE, or DELETE operation that the triggers generate are also sent
to the target database server. For example, the target table might receive
replicate data caused by a trigger that also executes locally. Depending on the
conflict-resolution rule and scope, these operations can result in errors. To
avoid this problem, define the replicate to not fire triggers on the target table.
For more information on triggers, see “Enabling Triggers” on page 6-14 and
the CREATE TRIGGER section in IBM Informix Guide to SQL: Syntax.
Overview of Enterprise Replication Administration 2-13
Transaction Processing Considerations
Sequence Objects
In bi-directional Enterprise Replication, if you replicate tables using sequence
objects for update, insert, or delete operations, the same sequences might be
generated on different servers at the same time, leading to collisions.
To avoid this problem, define sequence objects on each server so that the
generated sequences are disjoint. For more information, see the IBM Informix
Guide to SQL: Syntax.
Transaction Processing Considerations
Many variables affect the impact that replicating data has on your transaction
processing. This section discusses some of these variables:
■
Replication Volume
■
Distributed Transactions
■
Large Transactions
■
Supported SQL Statements
Replication Volume
To determine replication volume, you must estimate how many data rows
change per day. For example, an application issues a simple INSERT
statement that inserts 100 rows. If this table is replicated, Enterprise Replication must propagate and analyze these 100 rows before applying them to
the targets.
Distributed Transactions
A distributed transaction is a transaction that commits data in a single
transaction over two or more database servers.
Outside of the replication environment, Dynamic Server uses a two-phase
commit protocol to ensure that the transaction is either committed
completely across all servers involved or is not committed on any server. For
more information about the two-phase commit protocol, see the IBM Informix
Dynamic Server Administrator’s Guide.
2-14
IBM Informix Dynamic Server Enterprise Replication Guide
Transaction Processing Considerations
In a replication environment, when a distributed transaction is committed
across the source servers, each part of the transaction that applies to the local
server is written to the local logical logs. When Enterprise Replication
retrieves the transaction from the logical logs and forms its transaction data,
it is unable to identify the separate transaction data as the original single
transaction.
This situation could result in Enterprise Replication applying one transaction
successfully while aborting another. Another result might be a time lapse
between when Enterprise Replication applies the two transactions
(depending on the number of transaction data in each server’s send queue
and the state of the server).
Large Transactions
While Enterprise Replication is able to handle large transactions, it is
optimized for small transactions. For best performance, avoid replicating
large transactions.
Large transactions are handled with a grouper paging file located in
temporary smart large objects. Enterprise Replication can process transactions up to 4 TB in size. For more information, see “Setting Up the Grouper
Paging File” on page 4-18. You can view Enterprise Replication grouper
paging statistics with the onstat -g grp pager command (see “onstat -g grp”
on page C-6).
Instead of using Enterprise Replication to perform a batch job, use the BEGIN
WORK WITHOUT REPLICATION to run the batch job locally on each database
server. For more information, see “Blocking Replication” on page 4-22.
Supported SQL Statements
After you define Enterprise Replication on a table by including that table as
a participant in a replicate, you cannot execute any operation that changes
the structure of the table. In addition, you cannot exclusively lock a database
that is involved in replication (or perform operations that require an
exclusive lock). However, you can exclusively lock a table in a database.
Overview of Enterprise Replication Administration 2-15
Transaction Processing Considerations
Forbidden SQL Statements
You cannot use the following SQL statements against a table that is included
in a replicate:
■
DROP TABLE
■
RENAME TABLE
■
ALTER FRAGMENT
Limited SQL Statements
The following additional limitations also apply to tables defined for
replication:
■
Do not remove or disable the primary key constraint.
■
Do not rename, add, or drop columns.
■
Do not modify a column type.
■
Do not add or drop rowids.
■
Do not add or drop CRCOLS (shadow columns):
❑
ALTER TABLE ... ADD CRCOLS
❑
ALTER TABLE ... DROP CRCOLS
For more information about CRCOLS, see “Preparing Tables for Conflict Resolution” on page 4-25.
■
Do not modify the primary key columns.
For example, do not alter the column to add default values or other
constraints.
Important: Because primary key updates are sent as DELETE/INSERT statement
pairs, avoid changing the primary key and updating data in the same transaction.
■
Do not create or alter clustered indexes.
Important: Creating or altering a clustered index on a replicated table is not allowed.
To use the forbidden and limited SQL statements against a table defined for
replication, you must first stop (not suspend) the replicate that contains the
table, before running the SQL statement. After modifying the table, restart the
replicate. For more information, see “Managing Replicates” on page 7-7.
2-16
IBM Informix Dynamic Server Enterprise Replication Guide
Replication Environment Considerations
Permitted SQL Statements
Enterprise Replication permits the following SQL statements with no
limitations:
■
SET object mode (no disabling of primary key constraint)
■
START VIOLATIONS TABLE
■
STOP VIOLATIONS TABLE
■
CREATE TRIGGER
■
DROP TRIGGER
■
CREATE VIEW
■
DROP VIEW
■
CREATE SYNONYM
■
DROP SYNONYM
■
ADD INDEX
■
DROP INDEX
■
ALTER INDEX (except TO CLUSTER)
■
ALTER TABLE constraints (except for the primary key)
Replication Environment Considerations
Each replication system that you create affects your environment. Consider
the following when setting up your replication environment:
■
Time Synchronization
■
Using GLS with Enterprise Replication
Time Synchronization
Whenever you use replication that requires time stamp conflict resolution
(see “Conflict Resolution” on page 3-10), the operating system times of the
database servers that participate in the replicate must be synchronized. All
time stamps and internal computations are performed in Greenwich Mean
Time (GMT) and have an accuracy of plus or minus one second.
Overview of Enterprise Replication Administration 2-17
Replication Environment Considerations
Important: Enterprise Replication does not manage clock synchronization between
database servers that participate in a replicate.
To synchronize the time on one database server with the time on another
database server, use one of the following commands.
Operating System
Command
UNIX
rdate hostname
Windows
net time \\servername /set
net time /domain:servername /set
Important: These commands do not guarantee the times will remain synchronized.
You should use a product that supplies a network time protocol to ensure that times
remain synchronized. For information on tools for synchronizing the times, refer to
your operating system documentation.
GLS
Using GLS with Enterprise Replication
An Enterprise Replication system can include databases in different locales,
with the following restrictions:
■
When you define a database server for Enterprise Replication, that
server must be running in the English locale.
In other words, the syscdr database on every Enterprise Replication
server must be in the English locale.
■
You can replicate only between databases that are in the same locale.
■
Replicate names can be in the locale of the database.
Code-set conversion with the GLS library requires only those code-set
conversion files found in the $INFORMIXDIR/gls/cv9 directory.
■
For U.S. English, locales are handled automatically by the Client
SDK/Informix Connnect installation and setup.
■
For non-U.S. English locales, you might need to explicitly provide the
locale and conversion files.
For information about how to specify a nondefault locale and other considerations related to GLS locales, see the IBM Informix GLS User’s Guide.
2-18
IBM Informix Dynamic Server Enterprise Replication Guide
Enterprise Replication Data Types
Enterprise Replication Data Types
Enterprise Replication supports built-in data types and user-defined data
types, including row types and collection types. This section describes how
Enterprise Replication handles special data types:
■
Replicating on Heterogeneous Hardware
■
Replicating Simple and Smart Large Objects
■
Replicating Opaque User-Defined Data Types
For general information on data types, refer to the IBM Informix Guide to SQL:
Reference.
Important: Enterprise Replication does not support replication of simple large
objects stored on optical devices.
Important: Enterprise Replication does not verify the data types of columns in tables
that participate in replication. The replicated column in a table on the source database
server must have the same data type as the corresponding column on the target
server. The exception to this rule is cross-replication between simple large objects and
smart large objects.
If you use SERIAL or SERIAL8 data types, you must be careful when defining
serial columns. For more information, see “SERIAL Data Types and Primary
Keys” on page 2-12.
Replicating on Heterogeneous Hardware
Enterprise Replication supports all primitive data types across
heterogeneous hardware. If you define a replicate that includes nonprimitive data types (for example, BYTE and TEXT data), the application must
resolve data-representation issues that are architecture dependent.
If you use floating-point data types with heterogeneous hardware, you might
need to use IEEE floating point or canonical format for the data transfers. For
more information, see “Using the IEEE Floating Point or Canonical Format”
on page 6-13.
Overview of Enterprise Replication Administration 2-19
Enterprise Replication Data Types
Replicating Simple and Smart Large Objects
Enterprise Replication replicates:
■
Simple large object data types (TEXT and BYTE)
You can store simple large objects either in the tblspace with the rest
of the table columns (in a dbspace) or in a blobspace.
■
Smart large object data types (BLOB and CLOB)
You must store smart large objects in sbspaces.
For more information about database storage, see the IBM Informix Dynamic
Server Administrator’s Guide.
Replicating Simple Large Objects from Tblspaces
Simple large object data that is stored in tblspaces (rather than in blobspaces)
is placed in the logical log. Enterprise Replication reads the logical log to
capture and evaluate the data for potential replication.
Replicating Large Objects from Blobspaces or Sbspaces
Enterprise Replication does not retrieve simple large object data that is stored
in blobspaces and smart large object data that is stored in sbspaces from the
logical log. Instead, Enterprise Replication retrieves the large object data
directly from the blobspace or sbspace before sending the data to the target
database server.
It is possible that a transaction subsequent to the transaction being replicated
has modified or deleted a simple or smart large object that Enterprise Replication is trying to retrieve.
If Enterprise Replication encounters a row whose large object (simple or
smart) has been modified or deleted by a subsequent transaction, Enterprise
Replication does not send the data in the large object.
In most cases, the subsequent transaction that modified or deleted the large
object will also be replicated, so the data again becomes consistent once that
transaction is replicated. The data in the large object is inconsistent only in a
small window of time.
2-20
IBM Informix Dynamic Server Enterprise Replication Guide
Enterprise Replication Data Types
Keep in mind that if you specify sending only the columns that changed, the
data might not get updated during the next update of the row. For more
information, see “Replicating Only Changed Columns” on page 6-11.
Tip: Enterprise Replication allows cross-replication between simple large objects and
smart large objects. For example, you can replicate a simple large object on the source
database server to a smart large object on the target server or vice versa.
Conflict Resolution for Simple and Smart Large Objects
By default, Enterprise Replication performs all conflict detection and
resolution at the row level. However, in some cases, simple large object data
that is stored in a tblspace (rather than in a blobspace) is accepted by the
target server even if the row is rejected. This does not apply to simple large
object data that is stored in blobspaces or smart large object data that is stored
in sbspaces.
Time-Stamp Conflict Resolution for Simple Large Objects
When a replicated BYTE or TEXT column is modified on the source database
server, Enterprise Replication records the value of cdrserver and cdrtime for
that column. (For more information on cdrserver and cdrtime, see
“Preparing Tables for Conflict Resolution” on page 4-25.) If the column on
the target database server is also stored in a tablespace (rather than in a
blobspace), Enterprise Replication evaluates the cdrserver and cdrtime
values in the source and target columns and uses the following logic to
determine if the data is to be applied:
■
If the column of the replicated data has a time stamp that is greater
than the time stamp of the column on the local row, the data for the
column is accepted for replication.
■
If the server ID and time stamp of the replicated column are equal to
the server ID and time stamp on the column on the local row, the data
for the column is accepted for replication.
■
If there is no SPL conflict-resolution rule and the timestamps are
equal, then the row with the lowest CDR server ID wins.
Overview of Enterprise Replication Administration 2-21
Enterprise Replication Data Types
SPL Conflict Resolution for Simple Large Objects
If the replicate is defined with an SPL conflict-resolution rule, the SPL routine
must return the desired action for each BYTE or TEXT column. When the
routine is invoked, information about each BYTE or TEXT column is passed to
the routine as five separate fields. The following table describes the fields.
Argument
Description
Column size (INTEGER)
The size of the column (if data exists for this
column).
NULL if the column is NULL.
BLOB flag [CHAR(1)]
For the local row, the field is always NULL.
For the replicated row:
Column type [CHAR(1)]
ID of last update server
[CHAR(18)]
■
D indicates BYTE or TEXT data is sent from the
source database server.
■
U indicates BYTE or TEXT data is unchanged on
the source database server.
■
P indicates tablespace data.
■
B indicates blobspace data.
The ID of the database server that last updated
this column for tablespace data
For blobspace data: NULL
Last update time (DATETIME
YEAR TO SECOND)
For tablespace data: The date and time when the
data was last updated.
For blobspace data: NULL
For information on creating stored procedures, see the IBM Informix Guide to
SQL: Tutorial.
If the routine returns an action code of A, D, I, or U, the routine parses the
return values of the replicated columns. Each BYTE or TEXT column can
return a two-character field. For information about the action codes, refer to
“SPL Conflict-Resolution Rule” on page 3-14.
2-22
IBM Informix Dynamic Server Enterprise Replication Guide
Enterprise Replication Data Types
The first character defines the desired option for the BYTE or TEXT column, as
the following table shows.
Value
Function
C
Performs a time-stamp check for this column as used by the timestamp rule
N
Sets the replicate column to NULL
R
Accepts the replicated data as it is received
L
Retains the local data
The second character defines the desired option for blobspace data if the data
is found to be undeliverable, as the following table shows.
Value
Function
N
Sets the replicated column to NULL
L
Retains the local data (default)
O
Aborts the row
X
Aborts the transaction
SPL Conflict Resolution for Smart Large Objects
Enterprise Replication handles conflict resolution for smart large objects
using the SPL conflict-resolution rule in the same way as for simple large
objects. See “Conflict Resolution for Simple and Smart Large Objects” on
page 2-21.
Overview of Enterprise Replication Administration 2-23
Enterprise Replication Data Types
Distributing BYTE and TEXT Data
If Enterprise Replication processes a row and discovers undeliverable BYTE
or TEXT columns, the following actions can occur:
■
Any undeliverable columns are set to NULL if the replication
operation is an INSERT and the row does not already exist at the
target.
■
The old value of the local row is retained if the replication operation
is an UPDATE or if the row already exists on the target.
Considerations for Replicating Smart Large Objects
The following conditions apply to replicating smart large objects:
■
Enterprise Replication does not support replication of smart large
object updates performed outside of a row update.
■
After you update a smart large object that is referenced explicitly in
the table schema, you must update the referencing row before Enterprise Replication can replicate the updated smart large object. For
example:
UPDATE table_name SET smart_large_object_column = x
For more information, see the IBM Informix Guide to SQL: Syntax.
2-24
■
Enterprise Replication replicates updates to in-place smart large
objects by sending a new copy of the entire smart large object. Enterprise Replication does not send only the logged changes to update
smart large objects.
■
Enterprise Replication does not support sharing out-of-row data
(multiple references to a smart large object) during replication. If you
try to replicate multiple references to the same smart large object on
the source database server, Enterprise Replication does not re-create
those references on the target database server. Instead, Enterprise
Replication creates multiple smart large objects on the target
database server.
IBM Informix Dynamic Server Enterprise Replication Guide
Enterprise Replication Data Types
Replicating Opaque User-Defined Data Types
Enterprise Replication supports built-in data types and extended data types,
including opaque data types and user-defined types (UDTs). For a list of
supported extensible data types, see “Extensibility Enhancements” on page 6
of the Introduction.
Installing and Registering UDTs
You must install and register UDTs and their associated support routines on
all database servers participating in Enterprise Replication prior to starting
replication.
If you combine Enterprise Replication with High-Availability Data Replication (HDR), you must install UDTs on both HDR database servers, but only
register them on the primary HDR database server (see IBM Informix Dynamic
Server Administrator’s Guide).
UDT Support Functions
If you plan to replicate opaque user-defined types (UDTs), the UDT designer
must provide two support functions, streamwrite( ) and streamread( ). This
also applies to UDTs embedded in complex types.
The purpose of these functions is similar to the existing send( ) and receive( )
functions provided for client/server transmissions.
For information on writing these support functions, see the section on Enterprise Replication stream support functions in the IBM Informix DataBlade API
Programmer’s Guide.
When preparing a row that includes any UDT columns to queue to the target
system, Enterprise Replication calls the streamwrite( ) function on each UDT
column. The function converts the UDT column data from the in-server representation to a representation that can be shipped over the network. This
allows Enterprise Replication to replicate the column without understanding
the internal representation of the UDT.
On the target server, Enterprise Replication calls the streamread( ) function
for each UDT column that it transmitted using the streamwrite( ) function.
Overview of Enterprise Replication Administration 2-25
Enterprise Replication Data Types
Considerations for Replicating Opaque Data Types
The following conditions apply to replicating opaque data types:
■
The WHERE clause of the SELECT statement of the participant
modifier can reference an opaque UDT as long as the UDT is always
stored in row.
■
Any UDRs in a WHERE clause can use only parameters whose values
can be extracted fully from the logged row images, plus any optional
constants.
■
All of the columns in the SELECT statement of each participant
definition must be actual columns in that table. Enterprise Replication does not support virtual columns (results of UDRs on table
columns).
See “Participant Modifier” on page A-90 for information on the
WHERE clause in participant definitions.
■
You cannot use SPL routines for conflict resolution if the replicate
includes any UDTs in the SELECT statement or if the replicate is
defined to replicate only changed columns.
See “Conflict Resolution” on page 3-10 and “Replicating Only
Changed Columns” on page 6-11.
■
Enterprise Replication allows you to define replicates on tables that
contain one or more UDT columns as the primary key.
For more information, see the section on primary key constraints in
the IBM Informix Guide to SQL: Syntax.
Replicating Table Hierarchies
To replicate tables that form a hierarchy, you must define a separate replicate
for each table. If you define a replicate on a super table, Enterprise Replication does not automatically create implicit replicate definitions on the
subordinate tables.
Tip: Enterprise Replication does not require that the table hierarchies be identical on
the source and target servers.
You must use conflict resolution uniformly for all tables in the hierarchy. In
other words, either no conflict resolution for all tables or conflict resolution
for all tables.
2-26
IBM Informix Dynamic Server Enterprise Replication Guide
Chapter 3
Selecting the Enterprise Replication System and Network
Topology
Chapter 4
Preparing the Replication Environment
Chapter 5
Using High-Availability Data Replication with Enterprise
Replication
Chapter 6
Defining and Modifying Replication Servers, Replicates,
and Participants
Chapter 7
Managing Replication Servers and Replicates
Chapter 8
Creating and Managing Replicate Sets
Section II
Setting Up and Managing
Enterprise Replication
Chapter
Selecting the Enterprise
Replication System and
Network Topology
In This Chapter .
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3-3
Selecting the Enterprise Replication System
Primary-Target Replication System . .
Primary-Target Business Models .
Primary-Target Considerations . .
Update-Anywhere Replication System.
Conflict Resolution . . . . . . .
Conflict-Resolution Rule . . . .
Scope . . . . . . . . . . .
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3-3
3-3
3-4
3-8
3-8
3-10
3-11
3-17
Choosing a Replication Network Topology
Fully Connected Topology . . . . .
Hierarchical Replication Topologies. .
HR Topology Terminology . . .
Hierarchical Tree . . . . . . .
Forest of Trees . . . . . . . .
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3-18
3-19
3-19
3-20
3-21
3-22
3-2
IBM Informix Dynamic Server Enterprise Replication Guide
In This Chapter
This chapter describes types of replication systems provided by Enterprise
Replication and discusses the trade-offs associated with performance and
data availability.
Selecting the Enterprise Replication System
Enterprise Replication supports the following types of replication systems:
■
Primary-Target Replication System
■
Update-Anywhere Replication System
Primary-Target Replication System
In the primary-target replication system, the flow of information is in one
direction. That is, the primary always sends data to the target. The target does
not send data to the primary.
In primary-target replication, all database changes originate at the primary
database and are replicated to the target databases. Changes at the target
databases are not replicated to the primary.
Selecting the Enterprise Replication System and Network Topology 3-3
Primary-Target Replication System
A primary-target replication system can provide one-to-many or many-toone replication:
■
One-to-many replication
In one-to-many (distribution) replication, all changes to a primary
database server are replicated to many target database servers. Use
this replication model when information gathered at a central site
must be disseminated to many scattered sites.
■
Many-to-one replication
In many-to-one (consolidation) replication, many primary servers
send information to a single target server. Use this replication model
when many sites are gathering information (for example, local field
studies for an environmental study) that needs to be centralized for
final processing.
Primary-Target Business Models
Primary-target Enterprise Replication systems support the following
business models:
■
Data Dissemination
■
Data Consolidation
■
Workload Partitioning
■
Workflow Replication
Data Dissemination
Data dissemination supports business needs where data is updated in a
central location and then replicated to read-only sites. This method of distribution can be particularly useful for online transaction processing (OLTP)
systems where data is required at several sites, but because of the large
amounts of data, read-write capabilities at all sites would cripple the performance of the application. Figure 3-1 on page 3-5 illustrates data
dissemination.
3-4
IBM Informix Dynamic Server Enterprise Replication Guide
Primary-Target Replication System
Target
Target
Database
server
Database
server
(Read-only)
Primary
Figure 3-1
Data Dissemination
in a Primary-Target
Replication System
(Read-only)
Database
server
Target
Database
server
Target
(Read-write)
(Read-only)
Database
server
(Read-only)
Data Consolidation
As businesses reorganize to become more competitive, many choose to
consolidate data into one central database server. Data consolidation allows
the migration of data from several database servers to one central database
server. In Figure 3-2, the remote locations have read-write capabilities while
the central database server is read only.
Primary
Primary
Database
server
Database
server
(Read-write)
Target
Figure 3-2
Data Consolidation
in a Primary-Target
Replication System
(Read-write)
Database
server
Primary
Database
server
(Read-write)
Primary
(Read-only)
Database
server
(Read-write)
Selecting the Enterprise Replication System and Network Topology 3-5
Primary-Target Replication System
Businesses can also use data consolidation to off-load OLTP data for decision
support (DSS) analysis. For example, data from several OLTP systems can be
replicated to a DSS system for read-only analysis. Pay close attention to the
configuration of the tables from which data is replicated to ensure that each
primary key is unique among the multiple primary database servers.
Workload Partitioning
Workload partitioning gives businesses the flexibility of assigning data
ownership at the table-partition level, rather than within an application.
Figure 3-3 illustrates workload partitioning.
Asia-Pacific
U.S.A.
Database
server
Database
server
Database
server
A-P Partition
A-P Partition
A-P Partition
emp#
2994
4402
empname
N. Night
R. River
U.S.A. Partition
emp#
6398
9456
empname
D. Davis
E. Eldridge
Europe Partition
emp#
6520
3798
empname
P. Peters
G. Gladys
emp#
5783
1235
empname
A. Alder
M. Markar
emp#
5761
6642
emp#
9631
4951
empname
J. Jones
H. Height
emp#
3622
7333
empname
C. Cowpar
K. Kristen
Europe Partition
Europe Partition
emp#
8002
9966
empname
B. Barry
Z. Zachary
U.S.A. Partition
U.S.A. Partition
Owner of partition (Read-write)
3-6
Europe
empname
F. Fire
S. Smith
emp#
3711
5540
empname
L. Lane
T. Thomas
Read-only privileges
IBM Informix Dynamic Server Enterprise Replication Guide
Figure 3-3
Workload
Partitioning in a
Primary-Target
Replication System
Primary-Target Replication System
In Figure 3-3, the replication model matches the partition model for the
employee tables. The Asia-Pacific database server owns the partition and can
therefore update, insert, and delete employee records for personnel in its
region. The changes are then propagated to the U.S. and European regions.
The Asia-Pacific database server can query or read the other partitions
locally, but cannot update those partitions locally. This strategy applies to
other regions as well.
Workflow Replication
Unlike the data dissemination model, in a workflow-replication system, the
data moves from site to site. Each site processes or approves the data before
sending it on to the next site.
Order entry
Accounting
custno custname
1234
XYZ LTD
1235
XSPORTS
custno custname
1234
XYZ LTD
1235
XSPORTS
Order
processing
Order
processing
Inventory
management
Ship
custno custname
1234
XYZ LTD
1235
XSPORTS
custno custname
1234
XYZ LTD
1235
XSPORTS
Order
processing
Order
processing
Figure 3-4
A WorkflowReplication System
Where Update
Authority Moves
From Site to Site
Figure 3-4 illustrates an order-processing system. Order processing typically
follows a well-ordered series of steps: orders are entered, approved by
accounting, inventory is reconciled, and the order is finally shipped.
In a workflow-replication system, application modules can be distributed
across multiple sites and databases. Data can also be replicated to sites that
need read-only access to the data (for example, if order-entry sites want to
monitor the progress of an order).
A workflow-replication system, like the primary-target replication system,
allows only unidirectional updates. Many facts that you need to consider for
a primary-target replication system should also be considered for the
workflow-replication system.
However, unlike the primary-target replication system, availability can
become an issue if a database server goes down. The database servers in the
workflow-replication system rely on the data updated at a previous site.
Consider this fact when you select a workflow-replication system.
Selecting the Enterprise Replication System and Network Topology 3-7
Update-Anywhere Replication System
Primary-Target Considerations
The following sections describe some of the factors to consider when you
select a primary-target replication system:
■
Administration
Primary-target replication systems are the easiest to administer
because all updates are unidirectional and therefore, no data update
conflicts occur. Primary-target replication systems use the ignore conflict-resolution rule. See “Conflict-Resolution Rule” on page 3-11.
■
Capacity planning
All replication systems require you to plan for capacity changes. For
more information, see “Preparing Data for Replication” on
page 4-22.
■
High-availability planning
In the primary-target replication system, if a target database server
or network connection goes down, Enterprise Replication continues
to log information for the database server until it becomes available
again. If a database server is unavailable for some time, you might
want to remove the database server from the replication system. If
the unavailable database server is the read-write database server,
you must plan a course of action to change read-write capabilities on
another database server.
If you require a fail-safe replication system, you should select a highavailability replication system. For more information, see “HighAvailability Replication System” on page 5-3.
Update-Anywhere Replication System
In update-anywhere replication, changes made on any participating
database server are replicated to all other participating database servers. This
capability allows users to function autonomously even when other systems
or networks in the replication system are not available.
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IBM Informix Dynamic Server Enterprise Replication Guide
Update-Anywhere Replication System
Figure 3-5 illustrates an update-anywhere replication system.
Washington
service center
Database
server
Update
Update
Update
New York
service center
Figure 3-5
Update-Anywhere
Replication System
Database
server
Database
server
Los Angeles
service center
Because each service center can update a copy of the data, conflicts can occur
when the data is replicated to the other sites. To resolve update conflicts,
Enterprise Replication uses conflict resolution. For more information, see
“Conflict Resolution” on page 3-10.
Review the following information before you select your update-anywhere
replication system:
■
Administration
Update-anywhere replication systems allow peer-to-peer updates,
and therefore require conflict-resolution (see “Conflict Resolution” on
page 3-10). Update-anywhere replication systems require more
administration than primary-target replication systems.
■
Information consistency
Some risk is associated with delivering consistent information in an
update-anywhere replication system. You determine the amount of
risk based on the type of conflict-resolution rules and routines you
choose for resolving conflicts. You can configure an update-anywhere replication system where no data is ever lost; however, you
might find that other factors (for example, performance) outweigh
your need for a fail-safe mechanism to deliver consistent
information.
Selecting the Enterprise Replication System and Network Topology 3-9
Conflict Resolution
■
Capacity Planning
All replication systems require you to plan for capacity changes. For
more information, see “Preparing Data for Replication” on
page 4-22. In particular, if you choose the time stamp or time stamp
plus SPL routine conflict-resolution rule, see “Delete Table Disk
Space” and “Shadow Column Disk Space” on page 4-12.
■
High Availability
If any of your database servers are critical, consider using HDR to
provide backup servers. For more information, see “High-Availability Replication System” on page 5-3.
Conflict Resolution
When multiple database servers try to update the same row simultaneously
(the time stamp for both updates is the same GMT time), a collision exists. For
more information, see “Applying Replicated Data” on page 1-18. Enterprise
Replication must determine which new data to replicate. To solve conflict
resolution, you must specify the following for each replicate:
3-10
■
A conflict-resolution rule
■
The scope of the rule
IBM Informix Dynamic Server Enterprise Replication Guide
Conflict Resolution
Conflict-Resolution Rule
Enterprise Replication supports the following conflict-resolution rules.
Conflict Resolution Rule
Effect
Reference
Ignore
Enterprise Replication does not
attempt to resolve conflicts.
page 3-12
Time stamp
The row or transaction with the
most recent time stamp is
applied.
page 3-13
SPL routine
Enterprise Replication uses a
routine written in SPL (Stored
Procedure Language) that you
provide to determine which data
should be applied.
page 3-14
Time stamp with SPL
routine
If the time stamps are identical,
Enterprise Replication invokes an
SPL routine that you provide to
resolve the conflict.
page 3-13,
page 3-14
For all conflict-resolution rules except ignore, you must create shadow
columns in the tables on both the source and target servers involved in replication. For more information, see “Shadow Columns” on page 2-11.
Enterprise Replication supports up to two conflict-resolution rules for each
replicate: a primary rule and a secondary rule (if desired). Figure 3-6 shows
the valid combinations of Enterprise Replication conflict-resolution rules.
Figure 3-6
Valid Conflict-Resolution Rule Combinations
Primary Rule
Secondary Rule
Ignore
None
Time stamp
None
Time stamp
SPL routine
SPL routine
None
Selecting the Enterprise Replication System and Network Topology 3-11
Conflict Resolution
Ignore Conflict-Resolution Rule
The ignore conflict-resolution rule does not attempt to detect or resolve
conflicts. A row or transaction either applies successfully or it fails. A row
might fail to replicate because of standard database reasons, such as a
deadlock situation, when an application locks rows.
The ignore conflict-resolution rule can only be used as a primary conflictresolution rule and can have either a transaction or a row scope (as described
in “Scope” on page 3-17). Figure 3-7 describes the ignore conflict-resolution
rule.
Figure 3-7
Ignore Conflict-Resolution Rule
Database Operation
Row Exists in Target?
Insert
Update
Delete
No
Apply row
Discard row
Discard row
Yes
Discard row
Apply row
Apply row
When a replication message fails to apply to a target, you can spool the
information to one or both of the following directories:
■
Aborted-transaction spooling (ATS)
If selected, all buffers in a failed replication message that compose a
transaction are written to this directory.
■
Row-information spooling (RIS)
If selected, the replication message for a row that could not be
applied to a target is written to this directory.
For more information, see Chapter 9, “Monitoring and Troubleshooting
Enterprise Replication.”
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IBM Informix Dynamic Server Enterprise Replication Guide
Conflict Resolution
Time-Stamp Conflict-Resolution Rule
The time-stamp rule evaluates the latest time stamp of the replication against
the target and determines a winner.
Tip: All time stamps and internal computations are performed in Greenwich Mean
Time (GMT).
The time-stamp resolution rule behaves differently depending on which
scope is in effect:
■
Row scope
Enterprise Replication evaluates one row at a time. The row with the
most recent time stamp wins the conflict and is applied to the target
database servers. If an SPL routine is defined as a secondary conflictresolution rule, the routine resolves the conflict when the row times
are equal.
■
Transaction scope
Enterprise Replication evaluates the most recent row-update time
among all the rows in the replicated transaction. This time is compared to the time stamp of the appropriate target row. If the time
stamp of the replicated row is more recent than the target, the entire
replicated transaction is applied. If a routine is defined as a secondary conflict-resolution rule, it is used to resolve the conflict when the
time stamps are equal.
For more information, see “Scope” on page 3-17.
A secondary routine is invoked only if Enterprise Replication evaluates rows
and discovers equal time stamps.
If no secondary conflict-resolution rule is defined and the timestamps are
equal, the transaction from the database server with the lower value in the
cdrserver shadow column wins the conflict.
Figure 3-8 on page 3-14 shows how a conflict is resolved based on the latest
time stamp with row scope. The time stamp Tlast_update (the time of the last
update) represents the row on the target database server with the last (most
recent) update. The time stamp Trepl (the time when replication occurs) represents the time stamp on the incoming row.
Enterprise Replication first checks to see if a row with the same primary key
exists in either the target table or its corresponding delete table.
Selecting the Enterprise Replication System and Network Topology 3-13
Conflict Resolution
Important: Do not remove the delete tables created by Enterprise Replication. The
delete table is automatically removed when the last replicate defined with conflict
resolution is deleted.
If the row exists, Enterprise Replication uses the latest time stamp to resolve
the conflict.
Figure 3-8
Conflict Resolution Based on the Time Stamp
Database Operation
Row Exists
on Target?
Time Stamp
Insert
Update
Delete
No
n/a
Apply row
Apply row
Apply row
(Convert UPDATE to
INSERT)
(INSERT into Enterprise
Replication delete table)
Apply row
Apply row
Yes
Tlast_update <
Trepl
Apply row
Tlast_update >
Trepl
Discard row
Tlast_update =
Trepl
Apply row if no routine is defined as a secondary conflict-resolution rule.
Otherwise, invoke the routine.
(Convert INSERT to
UPDATE)
The time-stamp conflict-resolution rule assumes time synchronization
between cooperating Enterprise Replication servers. For more information,
see “Time Synchronization” on page 2-17.
SPL Conflict-Resolution Rule
Tip: The SPL rule allows you complete flexibility to determine which row prevails in
the database. However, for most users, the time-stamp conflict-resolution rule
provides sufficient conflict resolution.
You can assign an SPL routine as the primary conflict-resolution rule. If you
use an SPL routine as a secondary conflict-resolution rule, the time-stamp
conflict-resolution rule must be the primary rule.
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IBM Informix Dynamic Server Enterprise Replication Guide
Conflict Resolution
Important: The owner of an SPL routine used for conflict resolution must be the
same as the owner of the table.
Routines for conflict-resolution must be in SPL. Enterprise Replication does
not allow user-defined routines in C or in Java.
Important: You cannot use an SPL routine or a time stamp with an SPL routine if
the replicate is defined to replicate only changed columns or the replicated table
contains any extensible data types. See “Replicating Only Changed Columns” on
page 6-11.
Enterprise Replication passes the following information to an SPL routine as
arguments.
Argument
Description
Server name [CHAR(18)]
From the local target row
NULL if local target row does not exist
Time stamp (DATETIME YEAR TO SECOND)
From the local target row
NULL if local target row does not exist
Local delete-table indicator [CHAR(1)]
■
Y indicates the origin of the row is the delete table
or
■
K indicates the origin of the row is the replicate-key
delete row (for a key update that is sent as a key delete
and a key insert) because the local target row with the
old key does not exist
Local key delete-row indicator [CHAR(1)]
Server name [CHAR(18)]
Of the replicate source
Time stamp (DATETIME YEAR TO SECOND) From the replicated row
Replicate action type [CHAR(1)]
I- insert
D- delete
U- update
Local row data returned in regular SQL format Where the regular SQL format is taken from the SELECT
clause of the participant list
Replicate row data after-image returned in
regular SQL format
Where the regular SQL format is taken from the SELECT
clause of the participant list
Selecting the Enterprise Replication System and Network Topology 3-15
Conflict Resolution
The routine must set the following arguments before the routine can be
applied to the replication message.
Argument
Description
An indicator of the desired database operation
to be performed [CHAR(1)]
Same as the replicate action codes with the following
additional codes
■
A - Accept the replicated row and apply the column
values returned by the SPL routine.
For example, if Enterprise Replication receives an insert
and the row already exists locally, the insert is converted
to an update
■
S - Accept the replicated row and apply the column
values as received from the other site.
For example, if Enterprise Replication receives an insert
and the row already exists locally, the insert fails at the
time Enterprise Replication tries to apply the transaction
to the database, and the transaction aborts with an SQL
error.
■
O - Discard the replicated row.
■
X - Abort the transaction.
A non-zero integer value to request logging of
the resolution and the integer value in the
spooling files (INTEGER)
Logging value takes effect only if logging is configured
for this replicate.
The columns of the row to be applied to the
target table replicate action type in regular
SQL format
This list of column values is not parsed if the replicate
action type that the routine returns is S, O, or X.
You can use the arguments to develop application-specific routines. For
example, you can create a routine in which a database server always wins a
conflict regardless of the time stamp.
The following list includes some items to consider when you use an SPL
routine for conflict resolution:
3-16
■
Any action that a routine takes as a result of replication does not
replicate.
■
You cannot use an SPL routine to start another transaction.
■
Frequent use of routines might affect performance.
IBM Informix Dynamic Server Enterprise Replication Guide
Conflict Resolution
In addition, you must determine when the SPL routine executes:
■
■
An optimized SPL routine is called only when a collision is detected
and the row to be replicated fails to meet one of the following two
conditions:
❑
It is from the same database server that last updated the local
row on the target table.
❑
It has a time stamp greater than or equal to that of the local row.
A nonoptimized SPL routine executes every time Enterprise Replication detects a collision. By default, SPL routines are nonoptimized.
For information on specifying that the SPL routine is optimized, see “Conflict
Options” on page A-11.
Tip: Do not assign a routine that is not optimized as a primary conflict-resolution
rule for applications that usually insert rows successfully.
Scope
Each conflict-resolution rule behaves differently depending on the scope.
Enterprise Replication uses the following scopes:
■
Row scope
When you choose a row scope, Enterprise Replication evaluates one
row at a time. It only applies replicated rows that win the conflict resolution with the target row. If an entire replicated transaction
receives row-by-row evaluation, some replicated rows are applied
while other replicated rows might not be applied.
■
Transaction scope
When you choose a transaction scope, Enterprise Replication applies
the entire transaction if the replicated transaction wins the conflict
resolution. If the target wins the conflict (or other database errors are
present), the entire replicated transaction is not applied.
A transaction scope for conflict resolution guarantees transactional
integrity.
Selecting the Enterprise Replication System and Network Topology 3-17
Choosing a Replication Network Topology
Important: Enterprise Replication defers some constraint checking on the target
tables until the transaction commits. If a unique constraint or foreign-key constraint
violation is found on any row of the transaction at commit time, the entire transaction is rejected (regardless of the scope) and, if you have ATS set up, written to the
ATS directory. For more information, see “Aborted Transaction Spooling Files” on
page 9-3.
Choosing a Replication Network Topology
Enterprise Replication topology describes connections that replication servers
make to interact with each other. You must define the replication topology
within the topology of the physical network, but the replication topology is
not synonymous with the physical network topology. The order in which you
define the database servers for replication and the options that you use when
you define the database server determine the replication topology.
Enterprise Replication supports two types of network topology:
■
Fully Connected Topology
■
Hierarchical Replication Topologies
The topology that you choose influences the types of replication that you can
use. The next sections describe the topologies that Enterprise Replication
supports.
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IBM Informix Dynamic Server Enterprise Replication Guide
Fully Connected Topology
Fully Connected Topology
Fully connected replication topology indicates that all database servers
connect to each other and that Enterprise Replication establishes and
manages the connections. Replication messages are sent directly from one
database server to another. No additional routing is necessary to deliver
replication messages. Figure 3-9 shows a fully connected replication
topology. Each database server connects directly to every other database
server in the replication environment.
Figure 3-9
Fully Connected
Topology
Europe
Italy
Germany
France
If necessary, you can also add HDR and a backup server to any server to
provide high availability. For more information, see “High-Availability
Replication System” on page 5-3.
Hierarchical Replication Topologies
Enterprise Replication provides two types of Hierarchical Routing topology:
■
Hierarchical Tree
■
Forest of Trees
Selecting the Enterprise Replication System and Network Topology 3-19
Hierarchical Replication Topologies
HR Topology Terminology
Enterprise Replication uses the terms in the Figure 3-10 to describe Hierarchical Routing topology.
Figure 3-10
Replication Topology Terms
Term
Definition
Root server
An Enterprise Replication server that is the uppermost
level in a hierarchically organized set of information. The
root is the point from which database servers branch into
a logical sequence. All root database servers within Enterprise Replication must be fully interconnected.
Nonroot server
An Enterprise Replication server that is not a root
database server but has a complete global catalog and is
connected to its parent and to its children.
Tree
A data structure that contains database servers that are
linked in a hierarchical manner. The topmost node is
called the root. The root can have zero or more child
database servers; the root is the parent database server to
its children.
Parent-child
A relationship between database servers in a tree data
structure in which the parent is one step closer to the root
than the child.
Leaf server
A database server that has a limited catalog and no
children.
A root server is fully connected to all other root servers. It has information
about all other replication servers in its replication environment. Figure 3-9
on page 3-19 shows an environment with four root servers.
A nonroot server is similar to a root server except that it forwards all replicated
messages for other root servers (and their children) through its parent. All
nonroot servers are known to all root and other nonroot servers. A nonroot
server might or might not have children. All root and nonroot servers are
aware of all other servers in the replication environment.
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IBM Informix Dynamic Server Enterprise Replication Guide
Hierarchical Replication Topologies
Important: In Hierarchical Routing topologies, Enterprise Replication specifies the
synchronization server as the new server’s parent in the current topology. For more
information, see “Customizing the Replication Server Definition” on page 6-6 and
“cdr define server” on page A-19.
Hierarchical Tree
A hierarchical tree consists of a root database server and one or more database
servers organized into a tree topology. The tree contains only one root, which
has no parent. Each database server within the tree references its parent. A
database server that is not a parent is a leaf. Figure 3-11 illustrates a replication tree.
Figure 3-11
Hierarchical Tree
Topology
Asia
China
Japan
Guangzhou
Beijing
Hong Kong
Shanghai
In Figure 3-11, the parent-child relationship within the tree is as follows:
■
Asia is the parent of China and Japan.
■
China is the child of Asia and the parent of Beijing, Shanghai, and
Guangzhou.
■
Guangzhou is the child of China and the parent of Hong Kong.
Selecting the Enterprise Replication System and Network Topology 3-21
Hierarchical Replication Topologies
Asia is the root database server. Japan, China, and Guangzhou are nonroot
database servers. You can define Beijing, Shanghai, and Hong Kong as
either nonroot database servers or leaf database servers, depending on how
you plan to use them. The dashed connection from China to Shanghai
indicates that Shanghai is a leaf server.
Parent servers are good candidates for using HDR to provide backup servers.
For more information, see “Hierarchical Replication Topologies” on
page 3-19.
Forest of Trees
A forest of trees consists of several hierarchical trees whose root database
servers are fully connected. Each hierarchical tree starts with a root database
server. The root database servers transfer replication messages to the other
root servers for delivery to its child database servers. Figure 3-12 shows a
forest of trees.
North America
France
Europe
Germany
Asia
China
Japan
Guangzhou
Beijing
Hong Kong
Shanghai
3-22
IBM Informix Dynamic Server Enterprise Replication Guide
Figure 3-12
Forest-of-Trees
Topology
Hierarchical Replication Topologies
In Figure 3-12, North America, Asia, and Europe are root database servers.
That is, they are fully connected with each other. France and Germany are in
a tree whose root is Europe. Asia is the root for the six database servers in its
tree.
In a forest of trees, all replication messages from one tree to another must pass
through their roots. For example, a replication message from Beijing to
France must pass through China, Asia, and Europe.
Organizing the database servers in a hierarchical tree or a forest of trees
greatly reduces the number of physical connections that are required to make
a replication system. If all the database servers in Figure 3-12 were fully
connected, instead of being organized in trees, 55 connections would be
required.
To ensure that all servers retain access to the replication system, use HDR on
parent servers. For more information, see “Using HDR in a Forest of Trees
Topology” on page 5-7.
Selecting the Enterprise Replication System and Network Topology 3-23
Chapter
Preparing the Replication
Environment
In This Chapter .
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4-3
Preparing the Network Environment . . . . . . .
Setting Up the Hosts File . . . . . . . . . .
Setting Up the Services File. . . . . . . . . .
Setting Up the Trusted Environment . . . . . .
Verifying SQLHOSTS. . . . . . . . . . . .
Setting up Database Server Groups . . . . .
Hierarchical Routing Topologies and SQLHOSTS
Network Encryption and SQLHOSTS. . . . .
Testing the Network Environment . . . . . . .
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Preparing the Disk . . . . . . . . . . . .
Planning for Disk Space Requirements. . . .
Logical Log Configuration Disk Space . .
Logical Log Configuration Guidelines . .
Delete Table Disk Space . . . . . . .
Shadow Column Disk Space . . . . . .
Setting Up Send and Receive Queue Spool Areas
Transaction Record dbspace . . . . . .
Row Data sbspaces . . . . . . . . .
Setting Up the Grouper Paging File . . . . .
Creating ATS and RIS Directories . . . . .
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Preparing the Database Server Environment .
Setting Environment Variables . . . .
Setting Configuration Parameters . . .
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Preparing Data for Replication . . . . . . . . . . .
Preparing Consistent Data . . . . . . . . . . .
Blocking Replication . . . . . . . . . . . . .
Using DB-Access to Begin Work Without Replication
Using ESQL/C to Begin Work Without Replication .
Preparing to Replicate User-Defined Types . . . . .
Preparing to Replicate User-Defined Routines . . . .
Preparing Tables for Conflict Resolution . . . . . .
Preparing Logging Databases . . . . . . . . . .
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Loading and Unloading Data . . . .
High-Performance Loader . . .
onunload and onload Utilities .
dbexport and dbimport Utilities .
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Data Preparation Example .
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IBM Informix Dynamic Server Enterprise Replication Guide
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In This Chapter
This chapter covers the steps to take to prepare your environment for replicating data with Enterprise Replication: preparing the network environment,
the disk, the server environment, and the data.
Preparing the Network Environment
For more information on preparing the network environment, see the chapter
on client/server connectivity in the IBM Informix Dynamic Server Administrator’s Guide. See Appendix E, “Replication Examples,” for a sample setup.
To prepare your network environment
1.
Set up the hosts file.
For information, see “Setting Up the Hosts File” on page 4-4.
2.
Set up the services file.
For information, see “Setting Up the Services File” on page 4-4.
3.
Set up the trusted environment.
For information, see “Setting Up the Trusted Environment” on
page 4-5.
4.
Verify the SQLHOSTS information.
For information, see “Verifying SQLHOSTS” on page 4-5.
5.
Test the network environment.
For information, see “Testing the Network Environment” on
page 4-9.
Preparing the Replication Environment 4-3
Setting Up the Hosts File
Setting Up the Hosts File
First, make sure the hosts file includes the IP addresses and system names for
all database servers involved in Enterprise Replication.
Important: If you are using Domain Name Service (DNS) to identify IP addresses
and system names, you do not need to configure the hosts file.
The hosts file is in the following location.
Operating System
File
UNIX
/etc/hosts
Windows
%WINDIR%\system32\drivers\etc\hosts
Important: Leave a blank line at the end of the hosts file on Windows.
For example, your hosts file might look like the following:
123.456.789.1 sydney
123.456.789.2 melbourne
Setting Up the Services File
Next, make sure that the services file includes the port numbers and service
names for all the database servers involved in Enterprise Replication. The
services file is in the following location.
Operating System
File
UNIX
/etc/services
Windows
%WINDIR%\system32\drivers\etc\services
Important: Leave a blank line at the end of the services file on Windows.
4-4
IBM Informix Dynamic Server Enterprise Replication Guide
Setting Up the Trusted Environment
For example, your services file might look like the following:
sydney 5327/tcp
melbourne 5327/tcp
If the database servers reside on the same system, you must provide unique
port numbers for each.
Setting Up the Trusted Environment
To establish the trust relationship for all users, set up the hosts.equiv file. The
hosts.equiv file is in the following location.
Operating System
File
UNIX
/etc/hosts.equiv
Windows
%WINDIR%\system32\drivers\etc\hosts.equiv
For example, your hosts.equiv file might look like the following:
sydney
melbourne
Tip: Instead of allowing access to all users, you can set up .rhosts files in the home
directory of specific users. See your operating system documentation for more
information.
Verifying SQLHOSTS
Make sure that the SQLHOSTS file is set up properly on each server participating in replication.
Setting up Database Server Groups
Enterprise Replication requires that all database servers participating in
replication be members of database server groups. Each server in the enterprise must have a unique identifier; the database server group uniquely
identifies a server.
Preparing the Replication Environment 4-5
Verifying SQLHOSTS
If you are combining Enterprise Replication with HDR, both the primary and
secondary HDR servers must be members of the same database server group.
For more information, see “Managing Enterprise Replication with HighAvailability Data Replication” on page 5-11.
Typically, a server group includes only one database server. However, if the
computer has multiple network protocols or network interface cards, the
server group includes all aliases for the database server. Enterprise Replication treats the server group as one object, whether it includes one or several
database server names.
All Enterprise Replication commands and options use the name of the
database server group of the more familiar database server name (that is, the
name specified by the INFORMIXSERVER environment variable) for all references to database servers. The exception is the --connect option, which can
use both server name or group name. This manual also refers to a database
server group as a server group.
This manual uses the convention that the name of a database server group is
g_ followed by the name of a database server that is in the group. This use of
g_ is only a convention; g_ is not required syntax.
UNIX
Database Server Groups on UNIX
On UNIX, a database server group is defined in the sqlhosts file. The
following example shows a very simple sqlhosts file for four Enterprise
Replication servers, john, paul, george, and ringo and their database server
groups. The first line describes the database server group g_john, which
includes the database server john, and so on.
dbservername
nettype
hostname
servicename
options
g_john
john
g_paul
paul
g_george
george
g_ringo
ringo
group
ontlitcp
group
ontlitcp
group
ontlitcp
group
ontlitcp
sydney.australia.com
melbourne.australia.com
perth.australia.com
brisbane.australia.com
10110
2939
5329
10101
i=143
g=g_john
i=144
g=g_paul
i=145
g=g_george
i=146
g=g_ringo
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IBM Informix Dynamic Server Enterprise Replication Guide
Verifying SQLHOSTS
The following table describes the fields in the sqlhosts example above.
dbservername
Database server group name or database server name
nettype
Type of connection (composed of the database server
product, interface type, and network protocol)
hostname
The name of the computer where the database server
resides
servicename
The service name or port number entry in the services file
options
■
The g option specifies the name of the group to which the
database server belongs.
■
The i option specifies a unique identifier for the database
server. Make sure that this identifier is consistent for the
database server across all nodes in the enterprise.
Important: The network connection entry should appear immediately after the
database server group definition.
Important: If you use both DBSERVERNAME and DBSERVERALIASES,
DBSERVERNAME should refer to the network connection and not to a sharedmemory connection. For information about database server aliases, refer to the
IBM Informix Dynamic Server Administrator’s Guide.
For an example of an SQLHOSTS file when combining Enterprise Replication
and High-Availability Data Replication, see “Managing Enterprise Replication with High-Availability Data Replication” on page 5-11.
For more information about database server groups and setting up
SQLHOSTS, see the chapter on client/server communications in the
IBM Informix Dynamic Server Administrator’s Guide.
Windows
Database Server Groups on Windows
For information about preparing the SQLHOSTS connectivity information on
Windows, see Appendix F, “SQLHOSTS Registry Key.”
Preparing the Replication Environment 4-7
Verifying SQLHOSTS
Important: It is strongly recommended that you use IBM Informix Server Administrator (ISA), rather than regedt32, to set up the SQLHOSTS registry key and
database server group registry key on your Windows system. In addition, ISA allows
you to administer your replication system from a web browser. For more information,
see the Documentation Notes described in “Additional Documentation” on page 14
of the Introduction.
Hierarchical Routing Topologies and SQLHOSTS
For hierarchical routing (HR) topologies:
■
Root and nonroot servers must each have complete SQLHOSTS server
group information for the entire enterprise.
■
Each leaf server must have SQLHOSTS connectivity information only
for itself and its parent (hub).
Root and nonroot servers contain the complete global catalog; leaf servers do
not. For more information, see “HR Topology Terminology” on page 3-20
and “Global Catalog” on page 2-6.
Network Encryption and SQLHOSTS
Client/server network communication is encrypted by specifying the
ENCCSM module with the communications support module (CSM) option in
the SQLHOSTS file. However, Enterprise Replication can only be encrypted by
setting encryption configuration parameters. The ENCRYPT_CDR confirguration parameter must be set to 1 or 2 to allow encryption.
Important: Enterprise Replication cannot use a connection configured with a CSM.
To combine client/server network encryption with Enterprise Replication
encryption, configure two network connections for each database server. The
configuration in the SQLHOSTS file would look like the following example.
4-8
dbservername
nettype
hostname
servicename
options
g_group1
cdr1
serv1
group
ontlitcp
ontlitcp
texpdx
texpdx
mp.cdr1
mp.serv1
i=1
g=g_group1
csm=(ENCCSM)
IBM Informix Dynamic Server Enterprise Replication Guide
Testing the Network Environment
In this example, cdr1 and serv1 are two connection ports on the same
database server. Encrypted client/server communications uses the serv1
port, while encrypted Enterprise Replication uses the cdr1 port.
For more information on encrypting client/server network communications,
see the IBM Informix Dynamic Server Administrator’s Guide.
For more information on encrypting Enterprise Replication, see “Setting
Configuration Parameters” on page 4-20 and Appendix B, “Configuration
Parameter and Environment Variable Reference.”
Testing the Network Environment
Once you have verified the network setup information, test the network
environment.
To test the network environment
1.
Verify the network connection.
Use the ping command to test the connection between two systems.
For example, from sydney, test the connection to melbourne:
ping melbourne
2.
Test the trusted environment.
a.
Run dbaccess.
b.
Select the Connection menu option.
c.
Select the Connect menu option.
d.
Connect to the server group name and the server name of the
other hosts.
For example, if you are running dbaccess on sydney, and you are
testing the connection to a database server on melbourne, select
paul and g_paul.
e.
When prompted for the USER NAME, press ENTER.
If you can connect to the host database server, the host server is
trusted for user informix.
For more information, see the IBM Informix DB-Access User’s Guide.
Preparing the Replication Environment 4-9
Preparing the Disk
Preparing the Disk
Preparing your disk for Enterprise Replication includes the following:
■
Planning for Disk Space Requirements
■
Setting Up Send and Receive Queue Spool Areas
■
Creating ATS and RIS Directories
Planning for Disk Space Requirements
Enterprise Replication requires additional disk space for storing the logical
logs and, depending on your conflict-resolution configuration, delete tables
and shadow columns.
Logical Log Configuration Disk Space
The database server uses the logical log to store a record of changes to the
data since the last archive. Enterprise Replication requires the logical log to
contain entire row images for updated rows, including deleted rows.
The database server normally logs only columns that have changed. This
behavior is called the logical-log record reduction option. Enterprise
Replication deactivates this option for tables that participate in replication.
(The logical-log record reduction option remains enabled for tables that do
not participate in Enterprise Replication.) Enterprise Replication logs all
columns, not only the columns that have changed, which increases the size of
your logical log.
To determine the size of your logical log, examine your data activity for
normal operations and for the replication system you defined. Keep in mind
that defining replication on a table causes Enterprise Replication to
deactivate log reduction for that table, and that your transactions might log
more data.
Important: Enterprise Replication performs internal cleanup tasks based on how
often the log files switch. If the log files switch too frequently, Enterprise Replication
might perform excessive cleanup work.
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IBM Informix Dynamic Server Enterprise Replication Guide
Planning for Disk Space Requirements
Logical Log Configuration Guidelines
Use the following guidelines when configuring your logical log files:
■
Make sure that all logical log files are approximately the same size.
■
Make the size of the logical log files large enough so that the database
server switches log files no more than once every 15 minutes during
normal processing.
■
Plan to have sufficient logical-log space to hold at least four times the
maximum transaction size.
■
Set LTXEHWM (long-transaction, exclusive-access, high-watermark)
30 percent larger than LTXHWM (long-transaction high-watermark).
Important: If you specify that the database server allocate logical log files dynamically (DYNAMIC_LOGS), it is recommended that you set LTXEHWM to no higher
than 70 when using Enterprise Replication.
For more information about logical logs and these configuration parameters,
see IBM Informix Administrator’s Reference and IBM Informix Dynamic Server
Administrator’s Guide.
The database server can add dynamic logs when Enterprise Replication
enters blockout mode if the CDR_MAX_DYNAMIC_LOGS configuration
parameter is set to a non-zero integer. For more information, see “Preventing
DDRBLOCK Mode” on page 9-14.
Delete Table Disk Space
If you use the time stamp or time stamp and SPL routine conflict-resolution
rules, Enterprise Replication creates delete tables to keep track of modified
rows for conflict resolution. (Enterprise Replication creates delete tables only
for tables that have replicates defined with a conflict-resolution rule other
than ignore.) Delete tables handle conflicts such as when a DELETE or UPDATE
finds no corresponding row on the target. The DTCleaner thread removes a
row from the delete tables after all the servers have progressed beyond that
row. For more information, see “Conflict-Resolution Rule” on page 3-11.
Delete tables are created on the database server where the data originates and
on all the database servers to which data gets replicated. Delete tables are
stored in the same dbspaces, using the same fragmentation strategy, as their
base tables.
Preparing the Replication Environment 4-11
Setting Up Send and Receive Queue Spool Areas
To determine the disk space requirements to accommodate delete tables,
estimate how many rows will be deleted or modified. For example, if the base
table has 100 megabytes of data, but only half the rows might be deleted or
modified, then 50 megabytes is a reasonable estimate for the size of the delete
table.
Important: Do not remove the delete tables created by Enterprise Replication. The
delete table is automatically removed when the last replicate defined with conflict
resolution is deleted.
Shadow Column Disk Space
When you define a replicate that uses any conflict-resolution rule except
ignore, you must define shadow columns (CRCOLS) with the WITH CRCOLS
clause. The shadow columns, cdrserver and cdrtime, store server and timestamp information that Enterprise Replication uses for conflict resolution.
The two shadow columns are integers, which adds a total of 8 bytes to each
row in the table involved in a replicate that uses conflict resolution.
Tip: If you plan to use only the ignore conflict-resolution rule, you do not need to
define the cdrserver and cdrtime shadow columns.
For more information, see “Conflict-Resolution Rule” on page 3-11 and
“Preparing Tables for Conflict Resolution” on page 4-25.
Setting Up Send and Receive Queue Spool Areas
The term data queue refers to both the send queue and the receive queue. Enterprise Replication collects information from the logical logs and places the
data to be transferred in the send queue. Then Enterprise Replication
transfers the contents of the send queue to the receive queue on the target
server. Enterprise Replication on the target reads the data from the receive
queue and applies the changes to the tables on the target server.
The send and receive queues reside in memory and are managed by the
Reliable Queue Manager (RQM). The CDR_QUEUEMEM configuration
parameter (“CDR_QUEUEMEM Configuration Parameter” on page B-13)
specifies the amount of memory space that is available for the data queues.
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IBM Informix Dynamic Server Enterprise Replication Guide
Setting Up Send and Receive Queue Spool Areas
When a queue in memory fills (for the receive queue, this only occurs with
large transactions), the transaction buffers are written (spooled) to disk.
Spooled transactions consist of transaction records (headers that contain
internal information for Enterprise Replication), replicate information
(summaries of the replication information for each transaction), and row data
(the actual replicated data). Spooled transaction records and replication
records are stored in transaction tables and replication tables in a single
dbspace. Spooled row data is stored in one or more sbspaces.
Important: To prevent the send and receive queues from spooling to disk, see
“Preventing Memory Queues from Overflowing” on page 9-12.
Transaction Record dbspace
By default, the transaction records and replication records are stored in the
root dbspace. Because Enterprise Replication and other database servers
become unavailable if the root dbspace fills, you should define a single,
separate dbspace for the send and receive queue transaction records and
replication records before you define the replication server.
To determine the size of your transaction record dbspace, you must
determine the estimated number of transactions in a given period. You
should allocate 110 bytes per transaction to the dbspace and allocate enough
disk space to store 24 hours of transaction records. For example, if your
network is down for 24 hours, and you estimate that you will log 1000 transactions each day, the size of the transaction record dbspace should be at least
108 kilobytes (110 bytes * 1000 transactions / 1024).
To create the transaction record dbspace, use onspaces -c. For example, to
create a 110 kilobyte dbspace called er_dbspace using raw disk space on
UNIX with an offset of 0, enter:
onspaces -c -d er_dbspace -p /dev/raw_dev1 -o 0 -s 110
The pathname for the dbspace cannot be longer than 256 bytes.
Set the CDR_QHDR_DBSPACE configuration parameter
(“CDR_QHDR_DBSPACE Configuration Parameter” on page B-12) in the
ONCONFIG file to the location of the transaction record dbspace
(er_dbspace, in this example).
Warning: Do not change the value of CDR_QHDR_DBSPACE after you initialize
Enterprise Replication on a server.
Preparing the Replication Environment 4-13
Setting Up Send and Receive Queue Spool Areas
For information on creating dbspaces, see the chapter on managing disk
space in the IBM Informix Dynamic Server Administrator’s Guide and the utilities
chapter in the IBM Informix Administrator’s Reference.
Row Data sbspaces
Replicated data might include UDT and CLOB or BLOB data types, therefore,
the spooled row data is stored as smart large objects in one or more sbspaces.
Important: Before starting Enterprise Replication, you must create at least one
sbspace for spooled row data and set the CDR_QDATA_SBSPACE configuration
parameter to its location.
The CDR_QDATA_SBSPACE configuration parameter accepts multiple
sbspaces, up to a maximum of 32 sbspaces. Enterprise Replication can
support a combination of logging and non-logging sbspaces for storing
spooled row data. If CDR_QDATA_SBSPACE is configured for multiple
sbspaces, then Enterprise Replication uses all appropriate sbspaces in roundrobin order. For more information, see “CDR_QDATA_SBSPACE Configuration Parameter” on page B-11.
Creating sbspaces for Spooled Row Data
Follow these guidelines when creating sbspaces for spooled row data:
■
Create all the sbspaces of same default log mode type with the same
size.
■
Do not use Enterprise Replication row data sbspaces for non-Enterprise Replication activity.
■
Ensure that the sbspaces are sufficiently large.
To determine the size of your spooled row data sbspaces, determine
your log usage and then consider how much data you can collect if
your network goes down. For example, assume that you usually
log 40 megabytes of data each day, but only 10 percent of that is replicated data. If your network is down for 24 hours and you estimate
that you will log 4 megabytes of replicated data each day, the size of
the sbspaces you identify for the spooled row data must be a total of
at least 4 megabytes.
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IBM Informix Dynamic Server Enterprise Replication Guide
Setting Up Send and Receive Queue Spool Areas
On Windows, increase the resulting size of the sbspace by approximately a factor of two. (The default page size, the way that data maps
onto a page, and the number of pages written to disk differs on
Windows.) ♦
Windows
Warning: When the row data sbspaces fill, Enterprise Replication hangs until you
either resolve the problem that is causing Enterprise Replication to spool or allocate
additional disk space to the sbspaces. For more information, see “Preventing Memory
Queues from Overflowing” on page 9-12.
To create row data sbspaces, use the onspaces -c utility. For example, to create
a 4-megabyte sbspace, called er_sbspace, using raw disk space on UNIX with
an offset of 0, enter:
onspaces -c -S er_sbspace -p /dev/rdsk/c0t1d0s4 -o 0 -s 4000\
-m /dev/rdsk2/c0t1d0s4 0 \
-Df "AVG_LO_SIZE=2,LOGGING=OFF"
The pathname for an sbspace cannot be longer than 256 bytes.
The -m option specifies the location and offset of the sbspace mirror. The -Df
option specifies default behavior of the smart large objects stored in the
sbspace:
■
AVG_LO_SIZE (average large object size)
Set this parameter to the expected average transaction size (in kilobytes). The database server uses this value to calculate the metadata
size. The minimum value for AVG_LO_SIZE is 2 kilobytes, which is
appropriate for Enterprise Replication in most cases. (The default
value of AVG_LO_SIZE is 32 kilobytes.) If you set AVG_LO_SIZE to
larger than the expected transaction size, you might run out of metadata space. If you set AVG_LO_SIZE too small, you might waste space
on metadata.
■
LOGGING
Set this parameter to OFF to create an sbspace without logging. Set
this parameter to ON to create an sbspace with logging. It is recommended that you use a combination of logging and non-logging
sbspaces for Enterprise Replication. For more information, see “Logging Mode for sbspaces” on page 4-16.
Preparing the Replication Environment 4-15
Setting Up Send and Receive Queue Spool Areas
Set the CDR_QDATA_SBSPACE configuration parameter in the ONCONFIG file
to the location of the row data sbspace (er_sbspace, in this example). For
more information, see “CDR_QDATA_SBSPACE Configuration Parameter”
on page B-11.
Warning: Do not change the value of CDR_QDATA_SBSPACE after you initialize
Enterprise Replication.
Logging Mode for sbspaces
Enterprise Replication uses the default log mode that the sbspace was created
with for spooling row data.
Create sbspaces with a default logging mode of ON or OFF according to the
types of transactions Enterprise Replication replicates:
■
LOGGING=ON
Create sbspaces with LOGGING set to ON to support these situations:
❑
Replicated systems with HDR
Enterprise Replication must use logging sbspaces for transactions involved in HDR.
❑
Small transactions
Enterprise Replication uses logging sbspaces for transactions
that are less than a page size (2K or 4K) of replicated data.
For logging sbspaces, performance might be enhanced because logging mode enables asynchronous IO. However, a logging sbspace
consumes additional logical-log space.
■
LOGGING=OFF
Create sbspaces with LOGGING set to OFF to support replication of
large transactions (greater than a page size of replicated data).
It is recommended that you mirror non-logging sbspaces. For more
information, see the chapter on managing disk space in the
IBM Informix Dynamic Server Administrator’s Guide and the utilities
chapter in the IBM Informix Administrator’s Reference.
For non-logging sbspaces, performance is enhanced on the database
server when Enterprise Replication spools to disk because Enterprise
Replication writes less data to disk.
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IBM Informix Dynamic Server Enterprise Replication Guide
Setting Up Send and Receive Queue Spool Areas
Warning: Do not change the Enterprise Replication sbspace default log mode while
Enterprise Replication is running. To change the default log mode, follow the
procedure below.
You can change the default logging mode of the row data sbspace if you have
more than one sbspace specified by the CDR_QDATA_SBSPACE configuration
parameter.
To change the default logging mode of a row data sbspace
1.
Shut down the database server.
2.
Remove the sbspace from the CDR_QDATA_SBSPACE configuration
parameter value list.
3.
Start the database server in recovery mode.
4.
Wait for all the smart large objects to get deleted from the sbspace.
Use the onstat -g smb lod command to check for smart large objects
stored in an sbspace.
5.
Change the default logging mode for the sbspace.
6.
Add the sbspace name to the CDR_QDATA_SBSPACE configuration
parameter value list.
7.
Shut down and restart the database server using the onmode -ky and
oninit commands.
Dropping a Spooled Row Data sbspace
You can drop a row data sbspace if you have more than one sbspace specified
by the CDR_QDATA_SBSPACE configuration parameter.
Dropping a row data sbspace
1.
Shutdown the database server.
2.
Remove the sbspace from the CDR_QDATA_SBSPACE configuration
parameter value list.
3.
Start the database server in recovery mode.
Preparing the Replication Environment 4-17
Setting Up the Grouper Paging File
4.
Wait for all the smart large objects to get deleted from the sbspace.
Use the onstat -g smb lod command to check for smart large objects
stored in a sbspace.
5.
Drop the sbspace.
Warning: Do not drop an Enterprise Replication row data sbspace using the
onspaces -d -f (force) command.
Setting Up the Grouper Paging File
Enterprise Replication uses a grouper paging mechanism for evaluating
large transactions. A transaction is large if the portion to be replicated meets
at least one of the following conditions:
■
It has greater than 5,000 log records.
■
It exceeds one fifth the size of the value of the CDR_QUEUEMEM
onconfig variable.
■
It exceeds one tenth the size of the value of the SHMVIRTSIZE configuration variable.
The location of the sbspace used for the paging file is determined by the first
of the following ONCONFIG configuration parameters that is set:
■
SBSPACETEMP
■
SBSPACENAME
■
CDR_QDATA_SBSPACE
The best solution is to set up an unlogged sbspace, as specified by the
SBSPACETEMP configuration parameter. All updates to the paging files are
unlogged.
The size of the paging sbspace should be at least three time the size of the
largest transaction to be processed. This sbspace is also used by the database
server for other tasks; consider its overall usage when determining size
requirements.
Warning: If the paging sbspace fills, Enterprise Replication hangs until you allocate
additional disk space to the sbspace. If additional space is unavailable, use the cdr
stop command to stop replication.
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IBM Informix Dynamic Server Enterprise Replication Guide
Creating ATS and RIS Directories
Creating ATS and RIS Directories
The Aborted Transactions Spooling (ATS) and Row Information Spooling
(RIS) files contain information about failed transactions and aborted rows.
If you set up ATS and RIS, Enterprise Replication writes ATS and RIS files to
directories on the system:
■
ATS files
If you are using primary-target replication, create the ATS directory
on the target system. If you are using update-anywhere replication
(“Update-Anywhere Replication System” on page 3-8) and have
conflict resolution (“Conflict Resolution” on page 3-10) enabled, create the ATS directory on all participating replication systems.
■
RIS files
If you have conflict resolution enabled, create the RIS directory on all
participating replication systems.
The default location for these directories is /tmp (UNIX) or \tmp (Windows).
Specify a location other than /tmp or \tmp for the spooling directories.
Create the new location for these directories before you define the server for
replication.The pathnames for the ATS and RIS directories can be no longer
than 256 characters.
For information about ATS and RIS, refer to Chapter 9, “Monitoring and
Troubleshooting Enterprise Replication.”
Preparing the Database Server Environment
To prepare the database server environment, complete the following tasks:
■
Setting Environment Variables
■
Setting Configuration Parameters
If you are using High-Availability Data (HDR) replication with Enterprise
Replication, set up your HDR servers according to the instructions in the
section “HDR Requirements” on page 5-8.
Preparing the Replication Environment 4-19
Setting Environment Variables
Setting Environment Variables
To configure the database server environment, verify that the following
environment variables are set correctly:
■
INFORMIXDIR is set to the full path of the Informix directory.
■
INFORMIXSERVER is set to the name of the default database server.
For more information, see also “Connect Option” on page A-87.
■
INFORMIXSQLHOSTS is set to the full path to the SQLHOSTS file
(UNIX) or the SQLHOSTS registry host machine (Windows).
For more information, see the IBM Informix Administrator’s Reference.
Setting Configuration Parameters
In the ONCONFIG file for each database server, make sure that the following
configuration parameters are set:
■
DBSERVERNAME is set to the correct database server.
If you use both DBSERVERNAME and DBSERVERALIASES,
DBSERVERNAME should refer to the TCP connection and not to a
shared-memory connection. For information about database server
aliases, refer to the IBM Informix Dynamic Server Administrator’s Guide.
■
CDR_DBSPACE is set to the dbspace for the syscdr database. If not set,
the root dbspace is used.
■
CDR_QUEUEMEM is set to the maximum amount of memory to be
used for the send and receive queues.
■
CDR_QHDR_DBSPACE is set to the location of the transaction record
dbspace.
For more information, see “Transaction Record dbspace” on
page 4-13.
4-20
IBM Informix Dynamic Server Enterprise Replication Guide
Setting Configuration Parameters
■
CDR_QDATA_SBSPACE is set to the location of the row data sbspace.
If the CDR_QDATA_SBSPACE configuration parameter is not set in
ONCONFIG or the sbspace name specified by CDR_QDATA_SBSPACE
is invalid, Enterprise Replication fails to define the server.
For more information, see “Row Data sbspaces” on page 4-14.
■
CDR_SERIAL is set to enable control over generating values for serial
columns in tables defined for replication.
For more information, see “SERIAL Data Types and Primary Keys”
on page 2-12.
If you wish to encrypt network communications, in the ONCONFIG file for
each database server, make sure that the following configuration parameters
are set:
■
ENCRYPT_CDR is set to 1 or 2 to enable encryption. The default value
is 0, which prevents encryption.
■
ENCRYPT_CIPHER specifies which ciphers and cipher modes are
used for encryption.
■
ENCRYPT_MAC controls the level of Message Authentication Code
(MAC) used to ensure message integrity.
■
ENCRYPT_MACFILE is set to the full path and filenames of the MAC
files.
■
ENCRYPT_SWITCH is set to the number of minutes between
automatic renegotiations of ciphers and keys.
These configuration parameters are documented in Appendix B, “Configuration Parameter and Environment Variable Reference.”
Preparing the Replication Environment 4-21
Preparing Data for Replication
Preparing Data for Replication
The goal of data replication is to provide identical, or at least consistent, data
on multiple database servers. This section describes how to prepare the information in your databases for replication.
When you define a new replicate on tables with existing data on different
database servers, the data might not be consistent. Similarly, if you add a
participant to an existing replicate, you must ensure that all the databases in
the replicate have consistent values.
For more information, see “Data Preparation Example” on page 4-29.
Preparing Consistent Data
In most cases, preparing consistent data simply requires that you decide
which of your databases has the most accurate data and then copy that data
onto the target database. If the target database already has data, for data
consistency, you must remove that data before adding the copied data. For
information on loading the data, see “Loading and Unloading Data” on
page 4-26.
Blocking Replication
You might need to put data into a database that you do not want replicated,
perhaps for a new server or because you had to drop and re-create a table.
To block replication while you prepare a table, use the BEGIN WORK
WITHOUT REPLICATION statement. This starts a transaction that does not
replicate to other database servers.
The following code fragment shows how you might use this statement:
BEGIN WORK WITHOUT REPLICATION
LOCK TABLE office
DELETE FROM office WHERE description = 'portlandR_D'
COMMIT WORK
4-22
IBM Informix Dynamic Server Enterprise Replication Guide
Blocking Replication
The following list indicates actions that occur when a transaction starts with
BEGIN WORK WITHOUT REPLICATION:
■
SQL does not generate any values for the shadow columns (cdrserver
and cdrtime) for the rows that are inserted or updated within the
transaction. You must supply values for these columns with the
explicit column list. You must supply these values even if you want
the column values to be NULL.
■
To modify a table with shadow columns that is already defined in
Enterprise Replication, you must explicitly list the columns to be
modified. The following two examples show an SQL statement and
the correct changes to the statement to modify columns:
❑
If table_name1 is a table defined for replication, you must
change the following statement:
LOAD FROM filename INSERT INTO table_name1;
to:
LOAD FROM filename INSERT INTO table_name1 \
(list of columns);
The list of columns must match the order and the number of
fields in the load file.
❑
If table_name3 and table_name4 are tables defined for replication with the same schema, you must change the following
statement:
INSERT INTO table_name3 SELECT * FROM table_name4;
to an explicit statement, where col1, col2,..., colN are the columns
of the table:
INSERT INTO table_name3 VALUES
(cdrserver, cdrtime, col1, ..., colN)
cdrserver, cdrtime *
FROM table_name4;
The shadow columns (cdrserver and cdrtime) are not included
in an * list.
For more information about these statements, refer to the IBM Informix Guide
to SQL: Syntax.
Preparing the Replication Environment 4-23
Blocking Replication
Using DB-Access to Begin Work Without Replication
The following example shows how to use DB-Access to begin work without
replication as well as update the Enterprise Replication shadow columns
cdrserver and cdrtime:
DATABASE adatabase;
BEGIN WORK WITHOUT REPLICATION
INSERT into mytable (cdrserver, cdrtime, col1, col2, ....)
VALUES (10, 845484154, value1, value2, ....);
UPDATE mytable
SET cdrserver = 10, cdrtime = 945484154
WHERE col1 > col2;
COMMIT WORK
Using ESQL/C to Begin Work Without Replication
The following example shows how to use ESQL/C to begin work without
replication as well as update the Enterprise Replication shadow columns
cdrserver and cdrtime:
MAIN (argc, argv)
INT
argc;
CHAR *argv[];
{
EXEC SQL CHARstmt[256];
EXEC SQL database mydatabase;
sprintf(stmt, “BEGIN WORK WITHOUT REPLICATION”);
EXEC SQL execute immediate :stmt;
EXEC SQL insert into mytable (cdrserver, cdrtime,
col1, col2, ...)
values (10, 845494154, value1, value2, ...);
EXEC SQL update mytable
set cdrserver = 10, cdrtime = 845494154
where col1 > col2;
EXEC SQL commit work;
}
Important: You must use the following syntax when you issue the BEGIN WORK
WITHOUT REPLICATION statement from ESQL/C programs. Do not use the ‘$’
syntax.
sprintf(stmt, “BEGIN WORK WITHOUT REPLICATION”);
EXEC SQL execute immediate :stmt;
4-24
IBM Informix Dynamic Server Enterprise Replication Guide
Preparing to Replicate User-Defined Types
Preparing to Replicate User-Defined Types
You must install and register user-defined types on all database servers prior
to starting replication.
If you are using HDR with Enterprise Replication, follow the instructions in
the section “Preparing to Replicate UDTs, UDRs, and DataBlade Modules”
on page 5-10.
For Enterprise Replication to be able to replicate opaque user-defined types
(UDTs), the UDT designer must provide two support functions,
streamwrite( ) and streamread( ). For more information, see “Replicating
Opaque User-Defined Data Types” on page 2-25.
Preparing to Replicate User-Defined Routines
You must install and register user-defined routines on all database servers
prior to starting replication.
If you are using HDR with Enterprise Replication, follow the instructions in
the section “Preparing to Replicate UDTs, UDRs, and DataBlade Modules”
on page 5-10.
Preparing Tables for Conflict Resolution
To use any conflict-resolution rule other than ignore, you must define the
shadow columns, cdrserver and cdrtime.
Tip: If you plan to use only the ignore conflict-resolution rule, you do not need to
define the cdrserver and cdrtime shadow columns.
For more information about update-anywhere and conflict resolution, see
“Update-Anywhere Replication System” on page 3-8.
To define the shadow columns in your table, use the following statements:
■
For new tables, use:
CREATE TABLE table_name WITH CRCOLS;
■
For existing tables, use:
ALTER TABLE table_name ADD CRCOLS;
Preparing the Replication Environment 4-25
Preparing Logging Databases
Important: If a table already participates in Enterprise Replication, you must stop
replication before altering it with the ADD CRCOLS clause. For more information,
see “Stopping a Replicate” on page 7-8.
To drop the cdrserver and cdrtime shadow columns, use:
ALTER TABLE table_name DROP CRCOLS;
Tip: The ADD CRCOLS and DROP CRCOLS clauses to the ALTER TABLE statement
are now processed as in-place alters in most cases. For more information, see
“Functionality Improvements” on page 6 of the Introduction and the section on inplace alters in the Performance Guide. For more information on CREATE TABLE and
ALTER TABLE, see the sections in the IBM Informix Guide to SQL: Syntax.
Preparing Logging Databases
Databases on all server instances involved in replication must be created with
logging. For best results, use unbuffered logging. For more information, see
“Unbuffered Logging” on page 2-10.
Loading and Unloading Data
For loading data, you can use the following tools:
■
High-Performance Loader
■
onunload and onload Utilities
■
dbexport and dbimport Utilities
■
UNLOAD and LOAD Statements
When you unload and load data, you must use the same type of utility for
both the unload and load operations. For example, you cannot unload data
with the onunload utility and then load the data with a LOAD statement.
If you are using HDR with Enterprise Replication, follow the instructions in
the section “Loading and Unload Data” on page 5-10.
4-26
IBM Informix Dynamic Server Enterprise Replication Guide
Loading and Unloading Data
If the table that you are preparing for replication is in a database that already
uses replication, you might need to block replication while you prepare the
table. See “Blocking Replication” on page 4-22 for information on how to do
this.
If a table that you plan to replicate includes the shadow columns, cdrserver
and cdrtime, the statements that you use for unloading the data must
explicitly name the shadow columns. If you use * FROM table_name to the data
to unload, the data from the shadow columns will not be unloaded. To
include the shadow columns in the unloaded data, use a statement like the
following:
SELECT cdrserver, cdrtime, * FROM table_name
For more information, see “Shadow Columns” on page 2-11.
High-Performance Loader
The High-Performance Loader (HPL) provides a high-speed tool for moving
data between databases.
How you use the HPL depends on how you defined the tables to replicate. If
the table definition included the WITH CRCOLS clause, you must take special
steps when you unload the data.
If the table contains shadow columns, you must:
■
Include the cdrserver and cdrtime columns in your map when you
load the data.
■
Use express mode to load data that contains the cdrserver and
cdrtime columns. You must perform a level-0 archive after
completion.
You can also use deluxe mode without replication to load data. After a deluxe
mode load, you do not need to perform a level-0 archive. Deluxe mode also
allows you to load TEXT and BYTE data and opaque user-defined types.
For information about HPL, refer to the IBM Informix High-Performance Loader
User’s Guide.
Preparing the Replication Environment 4-27
Loading and Unloading Data
onunload and onload Utilities
You can use the onunload and onload utilities only to unload and load an
entire table. If you want to unload selected columns of a table, you must use
either unload or the HPL.
Important: You can only use onunload and onload in identical (homogeneous)
environments.
For more information about onunload and onload, see the IBM Informix
Migration Guide.
dbexport and dbimport Utilities
If you need to copy an entire database for replication, you can use the
dbexport and dbimport utilities. These utilities unload an entire database,
including its schema, and then re-create the database. If you want to move
selected tables or selected columns of a table, you must use some other utility.
For more information about dbexport and dbimport, see the IBM Informix
Migration Guide.
UNLOAD and LOAD Statements
The UNLOAD and LOAD statements allow you to move data within the
context of an SQL program.
If the table contains shadow columns, you must:
■
Include the cdrserver and cdrtime columns explicitly in your
statement when you unload your data.
■
List the columns that you want to load in the INSERT statement and
explicitly include the cdrserver and cdrtime columns in the list when
you load your data.
For more information about the UNLOAD and LOAD statements, see the
IBM Informix Guide to SQL: Syntax.
4-28
IBM Informix Dynamic Server Enterprise Replication Guide
Data Preparation Example
Data Preparation Example
The following steps provide an example of how to add a new participant
(delta) to an existing replicate using the LOAD, UNLOAD, and BEGIN WORK
WITHOUT REPLICATION statements. Replicate zebra replicates data from
table table1 for the following database servers: alpha, beta, and gamma.
The servers alpha, beta, and gamma belong to the server groups g_alpha,
g_beta, and g_gamma, respectively. Assume that alpha is the database server
from which you want to get the initial copy of the data.
To add a new participant to an existing replicate
1.
Declare server delta to Enterprise Replication. For example,
cdr def ser -c delta -I -S g_alpha g_delta
At the end of this step, all servers in the replication environment
include information in the syscdr database about delta, and delta
has information about all other servers.
2.
Add delta as a participant to replicate zebra. For example,
cdr cha rep -a zebra “dbname@g_delta:owner.table1”
This step updates the replication catalog. The servers alpha, beta,
and gamma do not queue any qualifying replication data for delta
because the replicate on delta, although defined, has not been
started.
3.
Suspend server to delta on alpha, beta, and gamma.
cdr sus ser g_alpha g_beta g_gamma
As a result of this step, replication data is queued for delta, but no
data is delivered.
4.
Start replication for replicate zebra on delta.
cdr sta rep zebra g_delta
This step causes servers alpha, beta, and gamma to start queueing
data for delta. No data is delivered to delta because delta is suspended. Then, delta queues and delivers qualifying data (if any) to
the other servers.
Do not run any transactions on delta that affect table table1 until you
finish the synchronization process.
Preparing the Replication Environment 4-29
Data Preparation Example
5.
Unload data from table table1 using the UNLOAD statement or the
unload utility on HPL.
6.
Copy the unloaded data to delta.
7.
Start transactions with BEGIN WORK WITHOUT REPLICATION, load
the data using the LOAD statement, and commit the transaction.
If you used the HPL to unload the data in step 5, then use the HPL
Deluxe load without replication to load the data into table1 on delta.
8.
Resume server delta on alpha, beta, and gamma.
This step starts the flow of data from alpha, beta, and gamma to
delta.
At this point you might see some transactions aborted because of
conflict. Transaction can abort because alpha, beta, and gamma
started queueing data from delta in step 4. However, those same
transactions might have been moved in steps 5 and 7.
You must declare replication on server delta and then immediately suspend
replication because, while you are preparing the replicates and unloading
and loading files, the other servers in the replicate (alpha, beta, and gamma)
might be collecting information that needs to be replicated. After you finish
loading the initial data to delta and resume replication, the information that
was generated during the loading process can be replicated.
4-30
IBM Informix Dynamic Server Enterprise Replication Guide
Chapter
Using High-Availability Data
Replication with Enterprise
Replication
In This Chapter .
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5-3
High-Availability Replication System . . . .
Using HDR in a Hierarchical Tree Topology .
Using HDR in a Forest of Trees Topology . .
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5-3
5-6
5-7
Preparing HDR Database Servers . . . . . . . . . . . .
HDR Requirements . . . . . . . . . . . . . . .
Setting Up Database Server Groups . . . . . . . . . .
Preparing to Replicate UDTs, UDRs, and DataBlade Modules .
Loading and Unload Data . . . . . . . . . . . . .
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5-8
5-8
5-9
5-10
5-10
Managing Enterprise Replication with High-Availability
Data Replication . . . . . . . . . . . . .
Row Data Sbspace Logging . . . . . . . . .
HDR Failure . . . . . . . . . . . . . . .
Performance Considerations . . . . . . . . .
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5-11
5-11
5-11
5-13
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5-2
IBM Informix Dynamic Server Enterprise Replication Guide
In This Chapter
This chapter covers how to include High-Availability Data Replication (HDR)
in your Enterprise Replication system. The following topics are covered:
■
The design of a high-availability replication system using HDR
■
Preparing HDR database server
■
Managing Enterprise Replication with HDR
For a complete description of HDR, see the IBM Informix Dynamic Server
Administrator’s Guide.
High-Availability Replication System
You can combine Enterprise Replication and HDR to create a high-availability replication system in which a critical read-write database server in an
Enterprise Replication system maintains a backup server with HDR.
An HDR system consists of two database servers: the primary database
server, which receives updates, and the secondary, read-only copy of the
primary database server. The secondary server is a mirror image of the
primary system and is in perpetual recovery mode, applying logical-log
records from the primary server to its dbspaces and sbspaces.
The HDR secondary server does not participate in Enterprise Replication; it
receives updates through HDR. When the HDR primary server receives an
update through Enterprise Replication, the transaction is not committed until
the log records containing that transaction are sent to the secondary server. If
the primary server becomes unavailable, you replace it with the secondary
server by switching the secondary server into standard mode and redirecting
connections to it.
Using High-Availability Data Replication with Enterprise Replication 5-3
High-Availability Replication System
High-availability replication systems are most useful for replication systems
in which the failure of a critical server prevents other servers from
participating in replication. Figure 5-1 illustrates the combination of a
primary-target replication system with a high-availability replication system.
Figure 5-1
Using HighAvailability with a
Primary-Target
Replication System
High-Availability Data Replication
HDR Secondary
(Read-only)
Enterprise
Replication
Target
Target
(Read-only)
(Read-only)
HDR Primary
(Read-write)
Target
(Read-only)
5-4
IBM Informix Dynamic Server Enterprise Replication Guide
Target
(Read-only)
High-Availability Replication System
If the primary server fails, the secondary server is set to standard mode, the
target database connections are redirected to it, and Enterprise Replication
continues, as illustrated in Figure 5-2.
Figure 5-2
Redirection to the
Secondary Database
Server
HDR Secondary (switched to standard mode)
(Read-write)
Target
Target
(Read-only)
(Read-only)
HDRPrimary
(offline)
(Read-write)
Target
(Read-only)
Target
(Read-only)
In an update-anywhere replication system, you can use HDR with any server
for which you need high availability, as illustrated in Figure 5-3.
Critical server
(HDR Primary)
Figure 5-3
Using High
Availability with an
Update-Anywhere
Replication System
Backup server
(HDR Secondary)
Using HDR with Enterprise Replication is particularly effective when you use
a hierarchical or a forest of trees topology.
Using High-Availability Data Replication with Enterprise Replication 5-5
Using HDR in a Hierarchical Tree Topology
Using HDR in a Hierarchical Tree Topology
With a hierarchical tree topology, parent servers are good candidates for
using HDR to provide backup servers. The following example is based on the
example in Figure 3-11 on page 3-21.
If China fails, then Beijing and Shanghai can no longer replicate with other
servers in the replication system; Guagnzhou and Hong Kong can only
replicate with each other. However, if China participated in HDR, when it
failed, the secondary server would replace it and replication could continue,
as illustrated in Figure 5-4.
Figure 5-4
Hierarchical Tree
Topology with HDR
Asia
China
China (offline)
Japan
secondary
primary
Guangzhou
Beijing
Hong Kong
Shanghai
In this example, Asia and Guangzhou, which are also parent servers, could
also benefit from using HDR to ensure high-availability.
5-6
IBM Informix Dynamic Server Enterprise Replication Guide
Using HDR in a Forest of Trees Topology
Using HDR in a Forest of Trees Topology
Use HDR to ensure that all servers retain access to the replication system in a
forest of trees topology.
For example, in Figure 3-12 on page 3-22, Asia, Europe, China, and
Guangzhou should use HDR to provide backup servers, as illustrated in
Figure 5-5.
Figure 5-5
HDR in a Forest-ofTrees Topology
Europe
secondary
North America
France
HDR
Europe
primary
Germany
Asia
Asia
secondary
HDR
primary
China
China
HDR
secondary
primary
Japan
Guangzhou
Guangzhou
Beijing
primary
HDR
secondary
Hong Kong
Shanghai
Using High-Availability Data Replication with Enterprise Replication 5-7
Preparing HDR Database Servers
Preparing HDR Database Servers
To prepare HDR database server for Enterprise Replication, perform the
following tasks:
■
Configure HDR database servers according to HDR requirements.
■
Set up the SQLHOSTS file with both the primary and secondary HDR
servers as members of the same database server group.
■
Install and register user-defined data types, user-defined routines,
and DataBlade modules.
■
Load data using backup and restore procedures.
Important: HDR does not support encryption. If you combine Enterprise Replication
with HDR, communication between Enterprise Replication servers and the HDR
primary server can be encrypted, but the communication between the HDR primary
server and the HDR secondary server cannot be encrypted. For more information, see
“ENCRYPT_CDR Configuration Parameter” on page B-15.
HDR Requirements
Make sure the HDR database servers meet HDR requirements in the following
categories:
■
Hardware and operating-system requirements
For example, the hardware and operating system of the computers
running the primary and secondary database servers must be
identical.
■
Database and data requirement
For example, all databases must have logging turned on and all data
must reside in logged dbspaces or sbspaces.
■
Database server configuration requirements
For example, the database server version, storage space and chunk
configuration, and many other configurations must be identical.
■
Connectivity
For example, the connectivity information on each of the computers
must identify the database server running on it and the other database server in the HDR pair.
5-8
IBM Informix Dynamic Server Enterprise Replication Guide
Setting Up Database Server Groups
For a complete list of configuration requirements, see the IBM Informix
Dynamic Server Administrator’s Guide.
Setting Up Database Server Groups
When defining an HDR server pair within Enterprise Replication, the HDR
server pair must appear to be a single logical entity within the replication
domain. To accomplish this, define the two HDR servers within the same
database server group in the SQLHOSTS file. For example, Figure 5-6 illustrates two Enterprise Replication nodes, one of which is an HDR pair.
serv1
Figure 5-6
Database Server
Groups for
Enterprise
Replication with
HDR
serv2
ER
HDR
serv1_sec
g_serv2
g_serv1
In this example, the HDR pair consists of the primary server, serv1, and the
secondary server, serv1_sec. These two servers belong to the same database
server group, g_serv1. The non-HDR server, serv2, belongs to the database
server group g_serv2. The following example displays the SQLHOSTS file for
this configuration.
dbservername
nettype
hostname
servicename
options
g_serv1
serv1
serv1_sec
g_serv2
serv2
group
ontlitcp
ontlitcp
group
ontlitcp
machine1pri
machine1sec
machine2
port1
port1
port1
i=1
g=g_serv1
g=g_serv1
i=2
g=g_serv2
Using High-Availability Data Replication with Enterprise Replication 5-9
Preparing to Replicate UDTs, UDRs, and DataBlade Modules
For more information on setting up the SQLHOSTS file, see “Verifying
SQLHOSTS” on page 4-5.
Either HDR or Enterprise Replication can be set up first on the HDR pair serv1
and serv1_sec, but Enterprise Replication cdr commands must be executed
only on the primary server. If any cdr commands are attempted on the
secondary server, a –117 error is returned: Attempting to process a cdr
command on an HDR secondary server.
Preparing to Replicate UDTs, UDRs, and DataBlade
Modules
If you are using HDR with Enterprise Replication with user-defined types,
user-defined routines, or DataBlade modules, perform the tasks shown in
Figure 5-7 on the primary and secondary database servers.
Figure 5-7
Preparing to Replicate UDTs, UDRs, and DataBlade Modules
Step
On the Primary
On the Secondary
1.
Install the user-defined types,
Install the user-defined types, user-
user-defined routines, or
DataBlade modules.
defined routines, or DataBlade
modules.
2.
Register the user-defined types,
user-defined routines, or
DataBlade modules.
When you start HDR, the user-defined types, user-defined routines, or
DataBlade modules are registered on the secondary database server. For
instructions on starting HDR, see the IBM Informix Dynamic Server Administrator’s Guide.
Loading and Unload Data
After you load data onto the HDR primary database server, use backup and
restore procedures to load the data onto the HDR secondary database server.
For instructions, see the IBM Informix Dynamic Server Administrator’s Guide.
5-10
IBM Informix Dynamic Server Enterprise Replication Guide
Managing Enterprise Replication with High-Availability Data Replication
Managing Enterprise Replication with HighAvailability Data Replication
This section describes how to manage Enterprise Replication with HDR in
the following areas:
■
Row data sbspace logging
■
HDR failure
■
Performance
Row Data Sbspace Logging
All sbspaces used by Enterprise Replication with HDR for spooled transaction row data must be created with logging enabled. For more information,
see “Row Data sbspaces” on page 4-14.
HDR Failure
If the primary server within an HDR pair fails, the secondary server can be
switched to standard mode by executing the onmode –d standard command.
However, you must manually start Enterprise Replication by executing the
cdr start command on that server. This is necessary to prevent Enterprise
Replication from starting on both servers in an HDR pair. Figure 5-8 shows
how to switch the secondary server to standard mode.
Figure 5-8
Switching the Secondary Server to Standard Mode
Step
On the Primary
1.
The server becomes unavailable.
2.
On the Secondary
onmode command
onmode -d standard
3.
cdr command
cdr start
Using High-Availability Data Replication with Enterprise Replication 5-11
HDR Failure
If you need to start the primary server while Enterprise Replication is
running on the secondary server, use the oninit –D command to prevent
Enterprise Replication and HDR from starting on the primary server.
If the problem has been resolved on the primary server and you wish to
reestablish it as the primary server, then first stop Enterprise Replication on
the secondary server. Otherwise, Enterprise Replication attempts to restart
on the primary server while it is still active on the secondary server.
Figure 5-9 shows how to reestablish the primary server.
Figure 5-9
Reestablishing the Primary Server
Step
On the Primary
1.
On the Secondary
cdr command
cdr stop
2.
onmode command
onmode -s
3.
onmode command
onmode -d secondary
4.
oninit
5.
cdr command
cdr start
If you want to split an active HDR pair into two stand-alone servers, then you
must be careful to avoid Enterprise Replication starting on either server after
they are split. To prevent Enterprise Replication and HDR from running, start
the database servers with the oninit –D command.
If you remove a server from an HDR pair, use the cdr remove command to
eliminate Enterprise Replication from that server. For example, the two HDR
servers are being split and the secondary server is to be used for reporting
purposes. After the report processing is complete, HDR can be reestablished.
Figure 5-10 shows how to remove a secondary server from HDR and Enterprise Replication.
5-12
IBM Informix Dynamic Server Enterprise Replication Guide
Performance Considerations
Figure 5-10
Removing the Secondary Server from HDR and ER
Step
On the Primary
On the Secondary
1.
onmode command
onmode command
onmode -d standard
onmode -d standard
2.
cdr command
cdr remove
If the HDR primary server has problems communicating to its secondary
server, Enterprise Replication is in a suspended state until one of the
following actions is taken:
■
Resolve the connection problem between HDR pairs.
■
Convert the primary server to standard mode.
For more information on managing HDR servers, see the IBM Informix
Dynamic Server Administrator’s Guide.
Performance Considerations
When Enterprise Replication is running on an HDR pair, some operations
cannot be performed until the logs are shipped to the secondary server. This
delay prevents possible inconsistency within the Enterprise Replication
domain during an HDR switch-over to a secondary server. Consequently,
there is a slight increase in replication latency when Enterprise Replication is
used with HDR. You can control this latency increase by setting the
DRINTERVAL configuration parameter to a low value.
Using High-Availability Data Replication with Enterprise Replication 5-13
Chapter
Defining and Modifying
Replication Servers,
Replicates, and Participants
In This Chapter .
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6-3
Initializing Database Servers
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6-4
Defining Replication Servers . . . . . . . .
Customizing the Replication Server Definition .
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6-5
6-6
Defining Replicates . . . . . . . . . . . . .
Defining Participants . . . . . . . . . . .
Defining Replicates on Table Hierarchies . .
Specifying Conflict Resolution Rules and Scope .
Specifying Replication Frequency . . . . . .
Setting Up Error Logging . . . . . . . . .
Replicating Only Changed Columns . . . . .
Using the IEEE Floating Point or Canonical Format
Enabling Triggers . . . . . . . . . . . .
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6-7
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6-10
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6-11
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6-14
Modifying Replication Servers .
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6-14
Modifying Replicates . . . . . .
Adding or Deleting Participants .
Changing Replicate Attributes .
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6-15
Resynchronizing Replication Servers.
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6-16
6-2
IBM Informix Dynamic Server Enterprise Replication Guide
In This Chapter
This chapter describes the steps for declaring a database server for Enterprise
Replication.
To define a replication server
1.
Initialize the database server.
For information, see “Initializing Database Servers” on page 6-4.
2.
Declare the database server to Enterprise Replication.
3.
For information, see “Defining Replication Servers” on page 6-5.
Once you define the server for replication, the server is known as a
replication server.
4.
Define replicates.
The replicate definition includes information about the participants,
replication options, frequency, and conflict-resolution rules and
scope.
For information, see “Defining Replicates” on page 6-7.
5.
Define participants.
A participant definition specifies the data (database, table, and columns) that should be replicated. Although you can define a replicate
with fewer, a replicate should contain two or more participants to be
useful.
For information, see “Defining Participants” on page 6-8.
Important: You must be the Enterprise Replication server administrator (“Enterprise Replication Server Administrator” on page 2-4) to define the replication server.
Defining and Modifying Replication Servers, Replicates, and Participants 6-3
Initializing Database Servers
This chapter also covers the following topics:
■
Modifying Replication Servers
■
Modifying Replicates
■
Resynchronizing Replication Servers
For information on managing your replication servers and replicates, see
“Managing Replication Servers and Replicates” on page 7-1.
Initializing Database Servers
The database server must be online before you can declare it for replication.
To bring the server from offline to online, issue the following command for
your operating system.
Operating System
Command
UNIX
oninit
Windows
starts dbservername
To bring the server from quiescent mode to online on either UNIX or
Windows, enter onmode -m.
For more information on initializing the database server, see the chapter on
database operating modes in the Administrator’s Guide for IBM Informix
Dynamic Server.
6-4
IBM Informix Dynamic Server Enterprise Replication Guide
Defining Replication Servers
Defining Replication Servers
Once you bring the database server online, the next step is to declare the
server to Enterprise Replication.
To define the replication server, use the cdr define server command. For
example:
cdr define server --init [--connect=server_name] \
options server_group_name
The --init option initializes the server. If INFORMIXSERVER is not set to the
server that you are defining, specify the --connect=server_name option
(“Connecting to Another Replication Server” on page 7-4).
Tip: All Enterprise Replication commands and options (except the --connect option
which can use both) use the name of the database server group (also known as a server
group) instead of the more familiar database server name for all references to database
servers. This manual uses the convention that the name of a server group is g_
followed by the server group name.
Important: If the CDR_SBSPACE configuration parameter is not set in ONCONFIG
or specifies an invalid sbspace, Enterprise Replication fails to define the server. For
more information, see “Row Data sbspaces” on page 4-14.
Defining and Modifying Replication Servers, Replicates, and Participants 6-5
Customizing the Replication Server Definition
Customizing the Replication Server Definition
When you define a replication server, you can change the following aspects
of the server in the replication environment:
■
Synchronize the new server’s global catalog (“Global Catalog” on
page 2-6) with another Enterprise Replication server.
For all servers except the first server you define in your Enterprise
Replication system, you must use --sync=sync_server in your server
definition to synchronize the global catalog with an existing server.
For Hierarchical Routing (HR) topologies, Enterprise Replication
also uses the synchronization server as the parent of the new server
in the current topology. For example, if you add a new server kauai
and synchronize its global catalog with hawaii, kauai is connected to
hawaii in the Enterprise Replication topology. For more information,
see “Choosing a Replication Network Topology” on page 3-18.
■
Set the idle timeout.
To specify the time (in minutes) that you want to allow the connection between two Enterprise Replication servers to remain idle
before disconnecting, use --idle=timeout.
Depending on the type of Enterprise Replication system (primary-target or
update-anywhere) and network topology (fully connected or hierarchical)
that you chose, set the following options:
■
Specify the location of the ATS directory.
To use ATS, specify the directory for the Aborted Transaction Spooling (ATS) files for the server using --ats=dir.
For more information, see “Creating ATS and RIS Directories” on
page 4-19 and Chapter 9, “Monitoring and Troubleshooting Enterprise Replication.”
■
Specify the location of the RIS directory.
To use RIS, specify the directory for the Row Information Spooling
(RIS) files for the server using --ris=dir.
For more information, see “Creating ATS and RIS Directories” on
page 4-19 and Chapter 9, “Monitoring and Troubleshooting Enterprise Replication.”
6-6
IBM Informix Dynamic Server Enterprise Replication Guide
Defining Replicates
■
Specify the type of server (hierarchical replication).
❑
To specify the server as a nonroot server, use --nonroot.
❑
To specify the server as a leaf server, use --leaf.
If neither --leaf nor --nonroot is specified, the server is defined as a
root server.
For more information, see “Hierarchical Replication Topologies” on
page 3-19.
For more information on network topology, see Chapter 3, “Selecting the
Enterprise Replication System and Network Topology.”
For more information, see “cdr define server” on page A-19.
Defining Replicates
To define a replicate, use the cdr define replicate command.
You must provide the following information in the replicate definition:
■
Participants
For more information, see “Defining Participants” on page 6-8.
■
Conflict resolution rules and scope
For more information, see “Specifying Conflict Resolution Rules and
Scope” on page 6-10.
■
Replication frequency
For more information, see “Specifying Replication Frequency” on
page 6-10.
■
Error logging
For more information, see “Setting Up Error Logging” on page 6-11.
■
Replicate full rows or only changed columns
For more information, see “Replicating Only Changed Columns” on
page 6-11.
Defining and Modifying Replication Servers, Replicates, and Participants 6-7
Defining Participants
■
IEEE or canonical message formats
For more information, see “Using the IEEE Floating Point or Canonical Format” on page 6-13.
■
Database triggers
For more information, see “Enabling Triggers” on page 14.
Once you define the replicate and participants, you must manually start the
replicate using the cdr start replicate command. See “Starting a Replicate” on
page 7-8.
Defining Participants
You must define participants for each server involved in the replicate in the
replicate definition using the cdr define replicate command.
Important: You cannot start and stop replicates that have no participants.
Each participant definition includes the following information:
■
Database server group name
■
Database in which the table to be replicated resides
■
Table name
■
Table owner
See “Table Owner” on page A-89.
■
SELECT statement and optional WHERE clause
See “Participant Modifier” on page A-90.
If you use a SELECT * FROM table_name statement, the tables must be
identical on all database servers defined for the replicate.
Important: Do not create more than one participant definition for each row and
column to replicate. If the participant is the same, Enterprise Replication attempts to
insert or update duplicate values during replication. For example, if one participant
modifier includes WHERE x < 50 and another includes WHERE x < 100, Enterprise
Replication sends the data twice.
6-8
IBM Informix Dynamic Server Enterprise Replication Guide
Defining Participants
In addition, for a primary-target replication system, you can specify the
participant type as either primary or target (receive-only). If you do not specify
the participant type, Enterprise Replication defines the participant as updateanywhere, by default. For more information, see “Primary-Target Replication
System” on page 3-3 and “Participant Type” on page A-89.
For example, in the following participant definition, the P indicates that in
this replicate, hawaii is a primary server.
“P db1@g_hawaii:informix.mfct” “select * from mfct” \
If any data in the selected columns changes, that changed data is to be sent to
the secondary servers.
In the following example, the R indicates that in this replicate, maui is a
secondary server:
“R db2@g_maui:informix.mfct” “select * from mfct”
The specified table and columns receive information sent from the primary
server. Changes to those columns on maui are not replicated.
Important: The R in the participant definition indicates that the table is receive-only
mode, not that the table is in read-only mode.
If you do not specify the participant type, Enterprise Replication defines the
participant as update-anywhere by default. For example:
“db1@g_hawaii:informix.mfct” “select * from mfct” \
“db2@g_maui:informix.mfct” “select * from mfct”
For more information, see “Participant” on page A-88.
Defining Replicates on Table Hierarchies
When you define replicates on inherited table hierarchies, use the following
guidelines to replicate operations:
■
For both the parent and child tables, define a replicate on each table.
■
For only the parent table (not the child table), define a replicate on the
parent table only.
■
For only the child table (not the parent table), define a replicate on the
child table only.
Defining and Modifying Replication Servers, Replicates, and Participants 6-9
Specifying Conflict Resolution Rules and Scope
Specifying Conflict Resolution Rules and Scope
For update-anywhere replication systems, you must specify the conflictresolution rules in the replicate definition using the --conflict=rule option.
The conflict resolution rules are:
■
ignore
■
timestamp
■
routine_name
If you use an SPL routine for your conflict-resolution rule, you can
also use the --optimize option to specify that the routine is
optimized.
For more information, see the following:
■
“Update-Anywhere Replication System” on page 3-8
■
“Conflict-Resolution Rule” on page 3-11
■
“Conflict Options” on page A-11
You can also specify the scope using the --scope=scope option:
■
transaction (default)
■
row
For more information, see “Scope” on page 3-17, and “Scope Options” on
page A-11.
Specifying Replication Frequency
The replication frequency options allow you to specify the interval between
replications, or the time of day when an action should occur. If you do not
specify the frequency, the default action is that replication always occurs
immediately when data arrives.
The frequency options are:
6-10
■
--immed
■
--every=interval
■
--at=time
IBM Informix Dynamic Server Enterprise Replication Guide
Setting Up Error Logging
For more information, see “Frequency Options” on page A-92.
Important: If you use time-based replication and two tables have referential
constraints, the replicates must belong to the same exclusive replicate set. For more
information, see “Exclusive Replicate Sets” on page 8-4.
Setting Up Error Logging
The Aborted Transaction Spooling (ATS) files and Row Information Spooling
(RIS) files contain information about failed transactions and aborted rows.
You can use this information to help you diagnose problems that arise during
replication. It is recommended that, until you become thoroughly familiar
with the behavior of the replication system, you select both options. For more
information about these files, refer to Chapter 9, “Monitoring and Troubleshooting Enterprise Replication.”
To configure your replicate to use ATS and RIS
1.
First, set up the ATS and RIS directories (“Creating ATS and RIS
Directories” on page 4-19).
2.
Then, when you define your server (“Defining Replication Servers”
on page 6-5), specify the location of the ATS and RIS directories.
3.
Now, when you define the replicate, specify that the replicate use
ATS and RIS by including the --ats and --ris options in the replicate
definition.
For more information, see “Special Options” on page A-13.
Replicating Only Changed Columns
By default, Enterprise Replication replicates the entire row, even if only one
column changed. (For more information on how Enterprise Replication
evaluates data for replication, see “Evaluating Data for Replication” on
page 1-10.)
You can change the default behavior to replicate only the columns that
changed. To replicate only changed columns, include the --fullrow n option
in the replicate definition.
Defining and Modifying Replication Servers, Replicates, and Participants 6-11
Replicating Only Changed Columns
Tip: Enterprise Replication always sends the primary key column, even if you
specify to replicate only changed columns.
Replicating only the columns that changed has the following advantages:
■
Sends less data
This is particularly useful when replicating large objects, such as
data stored as smart large objects and opaque user-defined types
(UDTs). For example, when you replicate a row with a large column
that changes infrequently and a small column that changes frequently, Enterprise Replication sends significantly less data each
time it updates the row if it only replicates the changed columns.
■
Uses fewer Enterprise Replication resources, such as memory
If Enterprise Replication replicates an entire row from the source, and the
corresponding row does not exist on the target, Enterprise Replication
applies the update as an INSERT, also known as an UPSERT, on the target. By
replicating the entire row, Enterprise Replication self-corrects any errors
during replication. If any errors occur in an update of the target database
server (for example, a large object is deleted before Enterprise Replication can
send the data), the next update from the source database server (a complete
row image) corrects the data on the target server.
Replicating only the columns that changed has the following disadvantages:
■
Enterprise Replication does not apply upserts.
If the row to replicate does not exist on the target, Enterprise Replication does not apply it. If you set up error logging (“Setting Up
Error Logging” on page 6-11), Enterprise Replication logs this information as a failed operation.
■
You cannot use the SPL routine or time stamp with SPL routine
conflict-resolution rules. For more information, see “Conflict
Resolution” on page 3-10.
■
You cannot use update-anywhere replication; doing so can result in
inconsistent conflict resolution.
■
All database servers in the enterprise must be Version 9.3 or later.
Enterprise Replication does not enforce this restriction. If you
attempt to replicate only changed columns to a pre-Version 9.3 database server, you will corrupt the data on that database server.
6-12
IBM Informix Dynamic Server Enterprise Replication Guide
Using the IEEE Floating Point or Canonical Format
Enterprise Replication logs bitmap information about the updated columns
in the logical-log file. For more information, see the CDR record type in the
logical-logs chapter in the IBM Informix Administrator’s Reference.
For more information on the --fullrow option, see “Special Options” on
page A-13.
Using the IEEE Floating Point or Canonical Format
The FLOAT and SMALLFLOAT data types are handled inconsistently across
different platforms. You can specify sending this data in either IEEE floating
point format or machine-independent decimal representation:
■
Enable IEEE floating point format to send all floating point values in
either 32-bit (for SMALLFLOAT) or 64-bit (for FLOAT) IEEE floating
point format.
To use IEE floating point format, include the --floatieee option in
your replicate definition.
It is recommended that you define all new replicates with the
--floatieee option.
■
Enable canonical format to send floating-point values in a machineindependent decimal representation when you replicate data
between dissimilar hardware platforms.
To use canonical format, include the --floatcanon option in your replicate definition. The --floatcanon option is provided for backwardcompatibility only; it is recommended that you use the --floatieee
option when defining new replicates.
■
If you specify neither IEEE or canonical formats, Enterprise Replication sends FLOAT and SMALLFLOAT data types as a straight copy
of machine representation. If you are replicating across different
platforms, replicated floating-point numbers will be incorrect.
For more information, see “Special Options” on page A-13.
Important: Once set, you cannot modify the replicate to change the --floatieee or
--floatcanon options.
Defining and Modifying Replication Servers, Replicates, and Participants 6-13
Enabling Triggers
Enabling Triggers
By default, when a replicate causes an insert, update, or delete on a target
table, triggers associated with the table are not executed. However, you can
specify that triggers are executed when the replicate data is applied by
enabling triggers in the replicate definition.
To enable triggers, include the --firetrigger option in your replicate
definition.
For information, refer to “Triggers” on page 2-13 and “Special Options” on
page A-13.
Modifying Replication Servers
To modify a replication server, use the cdr modify server command. With this
command, you can change the following attributes of the server:
■
Idle timeout
■
Location of the directory for the Aborted Transaction Spooling (ATS)
files
■
Location of the directory for the Row Information Spooling (RIS) files
For information about each of these attributes, see “Defining Replication
Servers” on page 6-5. For more information, see “cdr modify server” on
page A-55.
6-14
IBM Informix Dynamic Server Enterprise Replication Guide
Modifying Replicates
Modifying Replicates
You can modify replicates in two ways:
■
Adding or Deleting Participants
■
Changing Replicate Attributes
Adding or Deleting Participants
To be useful, a replicate must include at least two participants. You can define
a replicate (“Defining Replicates” on page 6-7) that has fewer than two participants, but before you can use that replicate, you must add more participants.
To add a participant to an existing replicate, use cdr change replicate --add.
For example, to add two participants to the sales_data replicate, enter:
cdr change replicate --add sales_data \
“db1@hawaii:jane.table1” “select * from table1” \
“db2@maui:john.table2” “select * from table2”
To delete a participant from the replicate, use cdr change replicate --delete.
For example, to delete these two participants from the replicate, enter:
cdr change replicate --delete sales_data \
“db1@hawaii:jane.table1” “db2@maui:john.table2”
For more information, see “cdr change replicate” on page A-4.
Changing Replicate Attributes
You can change the following attributes of a replicate using the cdr modify
replicate command:
■
Conflict-resolution rules and scope
■
Replication frequency
■
Error logging
■
Replicate full rows or only changed columns
■
Database triggers
■
Participant type
Defining and Modifying Replication Servers, Replicates, and Participants 6-15
Resynchronizing Replication Servers
Important: You cannot change the conflict resolution from ignore to a non-ignore
option (time stamp, SPL routine, or time stamp and SPL routine). You cannot change
a non-ignore conflict resolution option to ignore.
For information on each of these attributes, see “Defining Replicates” on
page 6-7.
For example, to change the replication frequency for the sales_data replicate
to every Sunday at noon, enter:
cdr modify replicate sales_data Sunday.12:00
For more information, see “cdr modify replicate” on page A-48.
Resynchronizing Replication Servers
You might want to resynchronize servers in your replication environment,
for example, if replicated tables between Enterprise Replication servers have
become out of sync after stopping and restarting replication for a server.
Warning: Make sure that there are no user transactions performing updates on any
replicated tables while you run this procedure.
To synchronize the replication g_papeete with the g_raratonga
1.
Suspend replication to the replication server group g_papeete.
See “Suspending Replication for a Server” on page 7-5.
2.
Unload the table from the server group g_raratonga.
See “Loading and Unloading Data” on page 4-26.
3.
Load the table on g_papeete and specify BEGIN WORK WITHOUT
REPLICATION.
See “Loading and Unloading Data” on page 4-26 and “Blocking Replication” on page 4-22.
4.
Resume replication to g_papeete.
See “Resuming a Suspended Replication Server” on page 7-6.
6-16
IBM Informix Dynamic Server Enterprise Replication Guide
Resynchronizing Replication Servers
Important: If tables that you are synchronizing include shadow columns, you must
explicitly unload and load these columns. If these values are not included, Enterprise
Replication inserts NULL values. For more information, see “Shadow Column Disk
Space” on page 4-12 and “Loading and Unloading Data” on page 4-26.
Defining and Modifying Replication Servers, Replicates, and Participants 6-17
Chapter
Managing Replication Servers
and Replicates
In This Chapter .
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7-3
Managing Replication Servers . . . . . .
Viewing Replication Server Attributes . .
Connecting to Another Replication Server
Stopping Replication on a Server. . . .
Restarting Replication on a Stopped Server
Suspending Replication for a Server . .
Resuming a Suspended Replication Server
Deleting a Replication Server . . . . .
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7-4
7-4
7-4
7-5
7-5
7-6
7-6
Managing Replicates . . . . . .
Viewing Replicate Properties . .
Starting a Replicate . . . . .
Stopping a Replicate . . . . .
Suspending a Replicate . . . .
Resuming a Suspended Replicate
Deleting a Replicate . . . . .
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7-7
7-8
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7-9
7-10
7-10
Managing Replication Server Network Connections
Viewing Network Connection Status . . . .
Dropping the Network Connection . . . . .
Reestablishing the Network Connection . . .
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7-2
IBM Informix Dynamic Server Enterprise Replication Guide
In This Chapter
This chapter covers how to manage your Enterprise Replication system,
including managing replication servers, replicates and participants in Enterprise Replication, replication server network connections, and Enterprise
Replication with High-Availability Data Replication.
Managing Replication Servers
The state of the server refers to the relationship between the source server and
the target server. To determine the current state of the server, use cdr list
server server_name. For more information about the possible server states,
see “The STATE Column” on page A-45.
This section contains information on performing the following tasks:
■
Viewing Replication Server Attributes
■
Connecting to Another Replication Server
■
Stopping Replication on a Server
■
Restarting Replication on a Stopped Server
■
Suspending Replication for a Server
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Resuming a Suspended Replication Server
■
Deleting a Replication Server
Managing Replication Servers and Replicates 7-3
Viewing Replication Server Attributes
Viewing Replication Server Attributes
Once you define a server for replication (“Defining Replication Servers” on
page 6-5), you can view information about the server using the cdr list server
command. If you do not specify the name of a defined server on the
command line, Enterprise Replication lists all the servers that are visible to
the current server. If you specify a server name, Enterprise Replication
displays information about the current server, including server ID, server
state, and attributes.
For more information, see “cdr list server” on page A-44.
Connecting to Another Replication Server
By default, when you view information about a server, Enterprise Replication connects to the global catalog of the database server specified by
$INFORMIXSERVER. You can connect to the global catalog of another
database server using the --connect option.
For example, to connect to the global catalog of the database server idaho,
enter:
cdr list server --connect idaho
For more information, see “Global Catalog” on page 2-6 and “Connect
Option” on page A-87.
Stopping Replication on a Server
Enterprise Replication starts automatically when you use cdr define server
to declare the server for replication. The replication threads continue running
until you shut the database server down or you remove the server with cdr
delete server. If you shut down the database server while Enterprise Replication is running, replication begins again when you restart the database
server. For more information about managing the database server, see the
chapter on database operating modes in the IBM Informix Dynamic Server
Administrator’s Guide.
7-4
IBM Informix Dynamic Server Enterprise Replication Guide
Restarting Replication on a Stopped Server
Generally, to stop Enterprise Replication on a server, you should bring down
the server. However, you might want to temporarily stop the Enterprise
Replication threads without stopping the server. To stop replication, use the
cdr stop command.
When you use cdr stop, Enterprise Replication stops capturing data to be
replicated. To ensure consistency, verify that no database update activity
occurs while Enterprise Replication is stopped. Replication threads remain
stopped (even if the database server is stopped and restarted) until you issue
a cdr start command.
Warning: When you stop replication on a server, you must ensure that the send
queues on the other Enterprise Replication servers participating in replication do not
fill.
For more information, see “cdr stop” on page A-71.
Restarting Replication on a Stopped Server
To restart replication for a stopped server, use the cdr start command. When
you restart the server, the Enterprise Replication threads start and continue.
Enterprise Replication resumes evaluating the logical logs at the replay
position (where Enterprise Replication stopped evaluating the logical log
when the server was stopped).
Warning: If the logical log corresponding to the replay position no longer exists, then
the restart partially fails and no database updates performed on the local database
server are replicated.
For more information, see “cdr start” on page A-65.
Suspending Replication for a Server
If you do not want to completely shut down the Enterprise Replication
threads, you can suspend replication of data to the server using the cdr
suspend server command. When replication is suspended to the server, the
source server queues replicated data, but suspends delivery of replicated
data to the target server. Note that this command does not affect the network
connection to the suspended server. The source server continues to send
other messages, such as acknowledgement and control messages.
Managing Replication Servers and Replicates 7-5
Resuming a Suspended Replication Server
For example, to suspend replication of data to the server group g_papeete
from the server group g_raratonga, enter:
cdr suspend server g_papeete g_raratonga
To suspend replication to g_papeete from all servers in the enterprise, enter:
cdr suspend server g_papeete
Warning: When you suspend replication on a server, you must ensure that the send
queues on the other Enterprise Replication servers participating in replication do not
fill.
For more information, see “cdr suspend server” on page A-81.
Resuming a Suspended Replication Server
To resume replication to a suspended server, use the cdr resume server
command. When you resume the server, the queued data is delivered.
For example, to resume replication to the g_papeete server group, enter:
cdr resume server g_papeete
If you do not specify the server group (g_papeete in the example), cdr
resume server resumes replication from all servers participating in
replication.
For more information, see “cdr resume server” on page A-63.
Deleting a Replication Server
To delete a replication server, use the cdr delete server command. You must
run the cdr delete server command twice.
For example, to remove the server group g_papeete from Enterprise Replication, set $INFORMIXSERVER to papeete and run the following commands:
cdr delete server g_papeete
cdr delete server --connect raratonga g_papeete
The first command deletes the local server group (g_papeete) from Enterprise Replication, and the second connects to another server in the replication
environment (raratonga) and deletes g_papeete from that server. The change
then replicates to the other servers in the replication environment.
7-6
IBM Informix Dynamic Server Enterprise Replication Guide
Managing Replicates
Warning: Avoid deleting an Enterprise Replication server and immediately
re-creating it with the same name. If you re-create the objects immediately (before the
operation finishes propagating to the other Enterprise Replication database servers in
the network), failures might occur in the Enterprise Replication system at the time of
the operation or later. For more information, see “Operational Considerations” on
page 2-8.
For more information, see “cdr delete server” on page A-28.
Managing Replicates
For more information about the possible replicate states, see “Displaying
Information About Replicates” on page A-40.
Important: If a replicate belongs to an exclusive replicate set, you cannot manage the
replicates individually. For more information, see“Exclusive Replicate Sets” on
page 8-4. With the exception of deleting the replicate, you must manage the replicate
as part of the exclusive replicate set. For more information, see “Managing Replicate
Sets” on page 8-6.
If the replicate belongs to a non-exclusive replicate set, you can manage the replicates
both individually and as part of the set. For more information, see“Non-Exclusive
Replicate Sets” on page 8-5.
Viewing Replicate Properties
Once you define a replicate, you can view the properties of the replicate using
the cdr list replicate command. For more information, see “Defining Replicates” on page 6-7. If you do not specify the name of a defined replicate on
the command line, Enterprise Replication lists detailed information on all the
replicates defined on the current server. If you use the brief option, Enterprise Replication lists participant information about all the replicates. If you
specify a replicate name, Enterprise Replication displays participant information about the replicate.
For information about this command, see “cdr list replicate” on page A-38.
Managing Replication Servers and Replicates 7-7
Starting a Replicate
Starting a Replicate
When you define a replicate, the replicate does not begin until you explicitly
change its state to active. When a replicate is active, Enterprise Replication
captures data from the logical log and transmits it to the participants.
Important: You cannot start replicates that have no participants.
To change the replicate state to active, use the cdr start replicate command.
For example, to start the replicate sales_data on the servers server1 and
server23, enter:
cdr start replicate sales_data server1 server23
This command causes server1 and server23 to start sending data for the
sales_data replicate.
If you omit the server names, this command starts the replicate on all servers
that are included in that replicate.
Warning: Run the cdr start replicate command on an idle system (no transactions
are occurring) or use the BEGIN WORK WITHOUT REPLICATION statement until
after you successfully start the replicate.
Important: If a replicate belongs to an exclusive replicate set, you must start the
replicate set to which the replicate belongs. For more information, see “Exclusive
Replicate Sets” on page 8-4 and “Starting a Replicate Set” on page 8-7.
For more information, see “cdr start replicate” on page A-67.
Stopping a Replicate
To stop the replicate, use the cdr stop replicate command. This command
changes the replicate state to inactive and deletes any data in the send queue
for that replicate. When a replicate is inactive, Enterprise Replication does not
capture, transmit, or process any database changes.
Important: You cannot stop replicates that have no participants.
For example, to stop the sales_data replicate on the servers server1 and
server23, enter:
cdr stop replicate sales_data server1 server23
7-8
IBM Informix Dynamic Server Enterprise Replication Guide
Suspending a Replicate
This command causes server1 and server23 to purge any data in the send
queue for the sales_data replicate and stops sending data for that replicate.
Any servers not listed on the command line continue to capture and send
data for the sales_data replicate (even to server1 and server23).
If you omit the server names, this command stops the replicate on all servers
that are included in that replicate.
Important: If a replicate belongs to an exclusive replicate set, you must stop the
replicate set to which the replicate belongs. For more information, see “Exclusive
Replicate Sets” on page 8-4 and “Stopping a Replicate Set” on page 8-7.
For more information, see “cdr stop replicate” on page A-73.
Suspending a Replicate
If you do not want to completely halt all processing for a replicate, you can
suspend a replicate using the cdr suspend replicate command. When a
replicate is suspended, the replicate captures and accumulates changes to the
source database, but does not transmit the captured data to the target
database.
Warning: Enterprise Replication does not support referential integrity if a replicate
is suspended. Instead, you should suspend a server. For more information, see
“Suspending Replication for a Server” on page 7-5.
For example, to suspend the sales_data replicate, enter:
cdr suspend replicate sales_data
Important: If a replicate belongs to an exclusive replicate set, you must suspend the
replicate set to which the replicate belongs. For more information, see “Exclusive
Replicate Sets” on page 8-4 and “Suspending a Replicate Set” on page 8-7.
For more information, see “cdr suspend replicate” on page A-77.
Managing Replication Servers and Replicates 7-9
Resuming a Suspended Replicate
Resuming a Suspended Replicate
To return the state of a suspended replicate to active, use the cdr resume
replicate command. For example:
cdr resume replicate sales_data
Important: If a replicate belongs to an exclusive replicate set, you must resume the
replicate set to which the replicate belongs. For more information, see “Exclusive
Replicate Sets” on page 8-4 and “Resuming a Replicate Set” on page 8-8.
For more information, see “cdr resume replicate” on page A-59.
Deleting a Replicate
To delete the replicate from the global catalog, use the cdr delete replicate
command. When you delete a replicate, Enterprise Replication purges all
replication data for the replicate from the send queue at all participating
database servers.
For example, to delete sales_data from the global catalog, enter:
cdr delete replicate sales_data
Warning: Avoid deleting a replicate and immediately re-creating it with the same
name. If you re-create the objects immediately (before the operation finishes propagating to the other Enterprise Replication database servers in the network), failures
might occur in the Enterprise Replication system at the time of the operation or later.
For more information, see “Operational Considerations” on page 2-8.
For more information, see “cdr delete replicate” on page A-24.
7-10
IBM Informix Dynamic Server Enterprise Replication Guide
Managing Replication Server Network Connections
Managing Replication Server Network Connections
Managing replication network connections consists of viewing the network
connection status, dropping the network connection, and reestablish a
dropped network connection.
Viewing Network Connection Status
To determine the current status of the network connection to each of the
servers participating in replication, use cdr list server. For more information
about network connection status, see “The STATUS Column” on page A-45.
For more information, see “cdr list server” on page A-44.
Dropping the Network Connection
To drop the Enterprise Replication network connection for a server, use the
cdr disconnect server command. When you drop the connection, Enterprise
Replication continues to function and queue transactions. For example, to
disconnect the network connection between the current replication server
and the server g_papeete, enter:
cdr disconnect server g_papeete
Warning: When you disconnect a server from Enterprise Replication, you must
ensure that the send queues on all other Enterprise Replication servers participating
in replication do not fill.
For more information, see “cdr disconnect server” on page A-32.
Managing Replication Servers and Replicates 7-11
Reestablishing the Network Connection
Reestablishing the Network Connection
To reestablish a dropped network connection, use the cdr connect server
command.
For example, to reestablish the network connection between the current replication server and the server g_papeete, enter:
cdr connect server g_papeete
For more information, see “cdr connect server” on page A-9.
7-12
IBM Informix Dynamic Server Enterprise Replication Guide
Chapter
Creating and Managing
Replicate Sets
In This Chapter .
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8-3
Creating Replicate Sets . . . . . . .
Exclusive Replicate Sets . . . . . .
Non-Exclusive Replicate Sets . . . .
Customizing the Replicate Set Definition
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Viewing Replicate Set Properties .
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8-6
Managing Replicate Sets . . .
Starting a Replicate Set . .
Stopping a Replicate Set . .
Suspending a Replicate Set .
Resuming a Replicate Set .
Deleting a Replicate Set . .
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8-6
8-7
8-7
8-7
8-8
8-8
Modifying Replicate Sets . . . . . . . . . . . . .
Adding or Deleting Replicates From a Replicate Set . .
Changing Replication Frequency For the Replicate Set .
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8-10
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8
8-2
IBM Informix Dynamic Server Enterprise Replication Guide
In This Chapter
This chapter covers creating replicate sets, viewing replicate set properties,
and managing and modifying replicate sets.
A replicate set is a collection of several replicates that you can manage together
as a unit. By default, you can manage replicates that belong to a replicate set
both individually and as part of the set, or as a set only.
Important: Enterprise Replication supports replicate sets for IBM Informix Dynamic
Server Version 9.3 and later only. You cannot define or modify replicate sets to
include replicates with participants that are Version 9.2 and earlier. In addition,
replicate sets are different from and incompatible with replicate groups (in
Version 9.2 and earlier).
To create, manage, or modify a replicate set on a database server other than
the server specified by $INFORMIXSERVER, use the --connect option
(“Connecting to Another Replication Server” on page 7-4) to connect to that
server.
Creating and Managing Replicate Sets 8-3
Creating Replicate Sets
Creating Replicate Sets
To create a replicate set, use the cdr define replicateset command.
Enterprise Replication supports two types of replicate sets: exclusive and nonexclusive.
Exclusive Replicate Sets
To maintain referential integrity between replicates that include tables that
have referential constraints placed on columns, you must create an exclusive
replicate set and add the replicate to it.
An exclusive replicate set has the following characteristics:
■
All replicates in an exclusive replicate set have the same state and
frequency settings. For more information, see “Displaying Information About Replicates” on page A-40.
■
When you create the replicate set, Enterprise Replication sets the
initial state of the replicate set to active.
■
You can manage the replicates in an exclusive replicate set only as
part of the set. Enterprise Replication does not support the following
actions for the individual replicates in an exclusive replicate set:
■
❑
Starting a Replicate
❑
Stopping a Replicate
❑
Suspending a Replicate
❑
Resuming a Suspended Replicate
Replicates that belong to an exclusive replicate set cannot belong to
any other replicate sets.
To create an exclusive replicate set, use the --exclusive (-X) option with cdr
define replicateset.
Important: Once you create an exclusive replicate set, you cannot change it to nonexclusive and vice versa.
8-4
IBM Informix Dynamic Server Enterprise Replication Guide
Non-Exclusive Replicate Sets
Non-Exclusive Replicate Sets
By default, cdr define replicateset creates non-exclusive replicate sets.
A non-exclusive replicate set has the following characteristics:
■
You can manage replicates that belong to a non-exclusive replicate
set both individually and as part of the set.
■
Because individual replicates in a non-exclusive replicate set can
have different states, the non-exclusive replicate set itself has no
state.
■
You should not use non-exclusive replicate sets for replicates that
include tables that have referential constraints placed on columns.
■
A replicate can belong to more than one non-exclusive replicate set.
Important: Once you create a non-exclusive replicate set, you cannot change it to
exclusive.
Use non-exclusive replicate sets if you want to add a replicate to more than
one replicate set. For example, you might want to create replicate sets to
manage replicates on the target server, table, or entire database. To do this,
create three non-exclusive replicate sets:
■
A set that contains the replicates that replicate to the target server
■
A set that contains the replicates on a particular table
■
A set that contains all the replicates
In this scenario, each replicate belongs to three non-exclusive replicate sets.
Customizing the Replicate Set Definition
You can specify the replication frequency (“Specifying Replication
Frequency” on page 6-10) for all the replicates when you define the replicate
set. For example, to define the non-exclusive replicate set sales_set with the
replicates sales_fiji and sales_tahiti and specify that the members of
sales_set replicate at 4:00 A.M. every day, enter:
cdr define replicateset --at 4:00 sales_set sales_fiji \
sales_tahiti
Creating and Managing Replicate Sets 8-5
Viewing Replicate Set Properties
To define the exclusive replicate set dev_set with the replicates dev_pdx and
dev_lenexa and specify that the members of dev_set replicate at 5:00 P.M.
every day, enter:
cdr define replicateset -X --at 17:00 dev_set dev_pdx\
dev_lenexa
Important: For replicates that belong to an exclusive replicate set, you cannot specify
the frequency for the individual replicates in the set.
For more information, see “cdr define replicateset” on page A-16.
Viewing Replicate Set Properties
To view the properties of the replicate set, use the cdr list replicateset
command. The cdr list replicateset command displays the replicate set name
and a list of the replicates that are members of the set. To find out more about
each replicate in the replicate set, see “Viewing Replicate Properties” on
page 7-7.
For more information, see “cdr list replicateset” on page A-42.
Managing Replicate Sets
When you create a replicate set, you can manage the replicates that belong to
that set together or individually. If the replicate set is exclusive, you can only
manage the individual replicates as part of the set.
Important: Performing an operation on a replicate set (except cdr delete replicateset) is equivalent to performing the operation on each replicate in the replicate set
individually.
For more information, see “Managing Replicates” on page 7-7.
8-6
IBM Informix Dynamic Server Enterprise Replication Guide
Starting a Replicate Set
Starting a Replicate Set
To change the state of all the replicates in the replicate set to active, use the
cdr start replicateset command. For example, to start the replicate set
sales_set, enter:
cdr start replicateset sales_set
Warning: Run the cdr start replicateset command on an idle system (when no
transactions are occurring) or use the BEGIN WORK WITHOUT REPLICATION
statement after you successfully start the replicate.
For more information, see “cdr start replicateset” on page A-69 and “cdr start
replicate” on page A-67.
Stopping a Replicate Set
To stop the replicates in the replicate set, use the cdr stop replicateset
command. This command changes the state of all the replicates in the set to
inactive.
For example, to stop the sales_set replicate set, enter:
cdr stop replicateset sales_set
For more information, see “cdr stop replicateset” on page A-75 and “cdr stop
replicate” on page A-73.
Suspending a Replicate Set
If you do not want to completely halt all processing for the replicates in a
replicate set, you can suspend the replicates in the set using the cdr suspend
replicateset command.
For example, to suspend the sales_set replicate set, enter:
cdr suspend replicateset sales_set
For more information, see “cdr suspend replicateset” on page A-79 and “cdr
suspend replicate” on page A-77.
Creating and Managing Replicate Sets 8-7
Resuming a Replicate Set
Resuming a Replicate Set
To return the suspended replicates in the replicate set to active, use the cdr
resume replicateset command. For example:
cdr resume replicateset sales_set
For more information, see “cdr resume replicateset” on page A-61 and “cdr
resume replicate” on page A-59.
Deleting a Replicate Set
To delete the replicate set, use the cdr delete replicateset command.
Tip: When you delete a replicate set, Enterprise Replication does not delete the replicates that are members of the replicate set. The replicates remain in the state they were
in when the set was deleted.
For example, to delete sales_set, enter:
cdr delete replicateset sales_set
Warning: Avoid deleting a replicate set and immediately re-creating it with the same
name. If you re-create the objects immediately (before the operation finishes propagating to the other Enterprise Replication database servers in the network), failures
might occur in the Enterprise Replication system at the time of the operation or later.
For more information, see “Operational Considerations” on page 2-8.
For more information, see “cdr delete replicateset” on page A-26.
8-8
IBM Informix Dynamic Server Enterprise Replication Guide
Modifying Replicate Sets
Modifying Replicate Sets
You can modify replicate sets in two ways:
■
Adding or Deleting Replicates From a Replicate Set
■
Changing Replication Frequency For the Replicate Set
Adding or Deleting Replicates From a Replicate Set
To add a replicate to an existing replicate set, use the command cdr change
replicateset --add. For example, to add two replicates to sales_set, enter:
cdr change replicateset --add sales_set sales_kauai \
sales_moorea
When you add a replicate to:
■
A non-exclusive replicate set, the state of the new replicate remains
as it was when you added it to the set. To bring all the replicates in
the non-exclusive set to the same state, use one of the commands
described in “Managing Replicate Sets” on page 8-6.
■
An exclusive replicate set, Enterprise Replication changes the
existing state and replication frequency settings of the replicate to the
current properties of the exclusive replicate set.
To delete a replicate from the replicate set, use cdr change replicate --delete.
For example, to delete the two replicates, sales_kauai and sales_moorea,
from the replicate set, enter:
cdr change replicateset --delete sales_set sales_kauai\
sales_moorea
When you add or remove a replicate from an exclusive replicate set that is
suspended or that is defined with a frequency interval, Enterprise Replication transmits all the data in the queue for the replicates in the replicate set
up to the point when you added or removed the replicate. For more information, see “Suspending a Replicate Set” on page 8-7 and “Frequency
Options” on page A-92.
For more information, see “cdr change replicateset” on page A-6.
Creating and Managing Replicate Sets 8-9
Changing Replication Frequency For the Replicate Set
Changing Replication Frequency For the Replicate Set
You can change the replication frequency for the replicates in an exclusive or
non-exclusive replicate set using the cdr modify replicateset command. For
more information, see “Specifying Replication Frequency” on page 6-10.
For example, to change the replication frequency for each of the replicates in
the sales_set to every Monday at midnight, enter:
cdr modify replicateset sales_set Monday.24:00
For more information, see “cdr change replicateset” on page A-6.
8-10
IBM Informix Dynamic Server Enterprise Replication Guide
Chapter
Monitoring and
Troubleshooting Enterprise
Replication
In This Chapter .
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9-3
Aborted Transaction Spooling Files . . . .
Preparing to Use ATS. . . . . . . .
About ATS Filenames . . . . . . .
About ATS File Information . . . . .
BYTE and TEXT Information in ATS Files.
Example 1 . . . . . . . . . .
Example 2 . . . . . . . . . .
Example 3 . . . . . . . . . .
Changed Column Information in ATS Files
BLOB and CLOB Information in ATS Files
UDT Information in ATS Files. . . . .
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9-7
9-7
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9-8
9-8
9-8
Row Information Spooling Files . . . . .
Preparing to Use RIS . . . . . . . .
About RIS Filenames . . . . . . . .
BYTE and TEXT Information in RIS Files .
Example 1 . . . . . . . . . .
Example 2 . . . . . . . . . .
Changed Column Information in RIS Files
BLOB and CLOB Information in RIS Files.
UDT Information in RIS Files . . . . .
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9-9
9-10
9-11
9-11
9-12
9-12
9-12
9-12
Preventing Memory Queues from Overflowing . . . . . .
Preventing DDRBLOCK Mode . . . . . . . . . .
Monitoring Disk Usage for Send and Receive Queue Spool
Increasing the Sizes of Storage Spaces . . . . . . . .
Recovering when Storage Spaces Fill . . . . . . . .
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9-12
9-14
9-16
9-16
9-17
9-2
Solving Common Configuration Problems .
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9-17
Enterprise Replication Event Alarms .
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9-20
IBM Informix Dynamic Server Enterprise Replication Guide
.
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In This Chapter
Enterprise Replication provides tools to help diagnose problems that arise
during replications. The Aborted Transaction Spooling (ATS) and Row Information Spooling (RIS) files contain information about failed transactions.
In addition, you can use tools provided with the server, such as the onstat
command, to display statistics that you can use to diagnose problems. For
more information on the onstat commands that are relevant to Enterprise
Replication, see Appendix C, “onstat Command Reference.”
This chapter covers the following topics:
■
Aborted Transaction Spooling Files
■
Row Information Spooling Files
■
Preventing Memory Queues from Overflowing
■
Solving Common Configuration Problems
■
Enterprise Replication Event Alarms
Aborted Transaction Spooling Files
When ATS is active, all failed replication transactions are recorded in ATS
files. Each ATS file contains all the information pertinent to a single failed
transaction. If a replicated transaction fails for any reason (constraint
violation, duplication, and so on), all the buffers in the replication message
that compose the transaction are written to a local operating-system file. You
can use the ATS files to identify problems or as input to custom utilities that
extract or reapply the aborted rows.
Monitoring and Troubleshooting Enterprise Replication 9-3
Preparing to Use ATS
Aborted-transaction spooling only occurs if the entire transaction is aborted.
Transactions defined with row scope that have aborted rows but are successfully committed on the target tables are not logged.
All rows that fail conflict resolution for a transaction that has row scope
defined are also written to the RIS file (“Row Information Spooling Files” on
page 9-9), if defined.
In some cases, such as with long transactions, the database server itself aborts
transactions. In these cases, Enterprise Replication does not generate an ATS
file.
Preparing to Use ATS
Failed transactions are not automatically recorded in ATS files.
To collect ATS information
1.
Create a directory for Enterprise Replication to store ATS files.
■
If you are using primary-target replication, create the directory
on the target system.
■
If you are using update-anywhere replication and have conflict
resolution enabled, create the directory on all participating replication systems.
For more information, see “Creating ATS and RIS Directories” on
page 4-19.
2.
When you define a server for Enterprise Replication, specify the
location of the ATS directory you created in step 1.
To do this, include the --ats option with the cdr define server
command.
If you do not specify an ATS directory, Enterprise Replication stores
the ATS files in the following directory:
UNIX
/tmp
Windows \tmp directory of the drive that contains
%INFORMIXDIR%
For more information, see “Creating ATS and RIS Directories” on
page 4-19.
9-4
IBM Informix Dynamic Server Enterprise Replication Guide
About ATS Filenames
3.
When you define a replicate, specify that ATS is active.
To do this, include the --ats option with the cdr define replicate
command.
For more information, see “Setting Up Error Logging” on page 6-11.
About ATS Filenames
When ATS is active, each aborted transaction is written to a file in the
specified directory.
The following table provides the naming convention for ATS files:
ats.target.source.threadId.timestamp.sequence
Name
Description
target
The name of the database server receiving this replicate transaction
source
The name of the database server that originated the transaction
threadId
The identifier of the thread that processed this transaction
timestamp
The value of the internal time stamp at the time that this ATS
instance was started
sequence
A unique integer, incremented by ATS each time a transaction is
spooled
The naming convention ensures that all filenames that ATS generates are
unique, and therefore name collision is unlikely. However, when ATS opens
a file for writing, any previous file contents will be overwritten. (ATS does not
append to a spool file; if a name collision does occur with an existing file, the
original contents of the file will be lost.)
The following is an example ATS filename for a transaction sent by server
g_amsterdam to server g_beijing:
ats.g_beijing.g_amsterdam.D_2.000529_23:27:16.6
Monitoring and Troubleshooting Enterprise Replication 9-5
About ATS File Information
About ATS File Information
The first three characters in each line of the ATS spool file describe the type of
information for the line, as the following table defines.
Label
Name
Description
TXH
Transaction
heading
This line contains information from the transaction
header, including the sending server ID and the commit
time, the receiving server ID and the received time, and
any Enterprise Replication, SQL, or ISAM error information for the transaction.
RRH
Replicated
row heading
This line contains header information from the replicated
rows, including the row number within the transaction,
the group ID, the replicate ID (same as replicate group ID
if replicate is not part of any replicate group), the database,
owner, table name, and the database operation.
RRS
Replicated
row shadow
columns
This line contains shadow column information from replicated rows, including the source server ID and the time
when the row is updated on the source server. This line is
printed only if the replicate is defined with a conflictresolution rule.
RRD
Replicated
row data
This line contains the list of replicated columns in the same
order as in the SELECT statement in the define replicate
command. Each column is separated by a ‘|’ and
displayed in ASCII format.
When the spooling program encounters severe errors (for
example, cannot retrieve replicate id for the replicated
row, unable to determine the replicated column’s type,
size, or length), it displays this row data in hexadecimal
format. The spooling program also displays the row data
in hexidecimal format if a row includes replicated UDT
columns.
9-6
IBM Informix Dynamic Server Enterprise Replication Guide
BYTE and TEXT Information in ATS Files
BYTE and TEXT Information in ATS Files
When the information recorded in the ATS file includes BYTE or TEXT data,
the replicated row data (RRD) information is reported, as the following
examples show.
Example 1
<1200, TEXT, PB 877(necromsv) 840338515(00/08/17 20:21:55)>
In this example:
■
1200 is the size of the data.
■
TEXT is the data type (it is either BYTE or TEXT).
■
PB is the storage type (PB when the BYTE or TEXT is stored in the
tablespace, BB for blobspace storage).
■
The next two fields are the server identifier and the time stamp for
the column if the conflict-resolution rule is defined for this replicate
and the column is stored in a tablespace.
Example 2
<500 (NoChange), TEXT, PB 877(necromsv) 840338478(00/08/17 20:21:18)>
In this example, (NoChange) after the 500 indicates that the TEXT data has a
size of 500, but the data has not been changed on the source server. Therefore
the data is not sent from the source server.
Example 3
<(Keep local blob),75400, BYTE, PB 877(necromsv) 840338515(00/08/17
20:21:55)>”)
In this example, (Keep local blob) indicates that the replicated data for this
column was not applied on the target table, but instead the local BYTE data
was kept. This usually happens when time-stamp conflict resolution is
defined and the local column has a time stamp greater than the replicated
column.
Monitoring and Troubleshooting Enterprise Replication 9-7
Changed Column Information in ATS Files
Changed Column Information in ATS Files
If you define a replicate to only replicate columns that changed, the RRD
entry in the ATS and RIS files show a ? for the value of any columns that are
not available. For example:
RRD 427|amsterdam|?|?|?|?|?|?|?|?|?|?|?
For more information, see “Replicating Only Changed Columns” on
page 6-11).
BLOB and CLOB Information in ATS Files
If a replicate includes one or more BLOB or CLOB columns, the RRD entry in
the ATS file displays the smart blob metadata (the in-row descriptor of the
data), not the smart blob itself, in hexadecimal format in the ATS file. See
“UDT Information in ATS Files” for an example.
UDT Information in ATS Files
If a replicate includes one or more UDT columns, the RRD entry in the ATS file
displays the row data in hexadecimal format in the ATS file. This representation includes a column number in the form Cnnn where nnn is the column
number. For example:
RRS
RRS
RRD
RRD
9-8
C001
C002
C003
C004
0000000a
394925cb
00000016
074b4d70 5d6f784a 00000000 00000000
IBM Informix Dynamic Server Enterprise Replication Guide
^@
^@9I%Ë
^@
^@.KMp]oxJ
Row Information Spooling Files
Row Information Spooling Files
Row Information Spooling logs the following types of information in RIS
files:
■
Individual aborted row errors
■
Replication exceptions (such as when a row is converted by Enterprise Replication from insert to update, or from update to insert, and
so on)
■
Special SPL routine return codes, as defined by the application (if an
SPL routine is called to resolve a conflict)
Preparing to Use RIS
Failed transactions are not automatically recorded in RIS files.
To collect RIS information
1.
Create a directory for Enterprise Replication to store RIS files.
If you have conflict resolution enabled, create the directory on all
participating replication systems.
For more information, see “Creating ATS and RIS Directories” on
page 4-19.
2.
When you define a server for Enterprise Replication, specify the
location of the RIS directory you created in step 1.
To do this, include the --ris option with the cdr define server
command.
If you do not specify an RIS directory, Enterprise Replication stores
the RIS files in the following directory:
UNIX
/tmp
Windows
\tmp directory of the drive that contains
%INFORMIXDIR%
Monitoring and Troubleshooting Enterprise Replication 9-9
About RIS Filenames
If the default directory does not exist, Enterprise Replication returns
an error.
For more information, see “Creating ATS and RIS Directories” on
page 4-19.
3.
When you define a replicate, specify that RIS is active.
To do this, include the --ris option with the cdr define replicate
command.
For more information, see “Setting Up Error Logging” on page 6-11.
About RIS Filenames
The RIS row information is written at the time that the data-synchronization
component finishes processing the replicated row and can therefore also
provide the local row information. The RIS filename algorithm is analogous
to the one that ATS uses, with the ats prefix replaced by ris. The RIS file that
corresponds to the ATS file described in the previous section is, for example:
ris.g_beijing.g_amsterdam.D_2.000529_23:27:16.5
For more information, see “About ATS Filenames” on page 9-5.
9-10
IBM Informix Dynamic Server Enterprise Replication Guide
BYTE and TEXT Information in RIS Files
In addition to the four types of records printed in ATS, the RIS file also
includes the following information.
Label
Name
Description
LRH
Local-row header
Indicates if the local row is found in the delete table
and not in the target table.
LRS
Local-row shadow
columns
Contains the server id and the time when the row is
updated on the target server. This line is printed only
if the replicate is defined with a conflict-resolution
rule.
LRD
Local-row data
Contains the list of replicated columns extracted
from the local row and displayed in the same order
as the replicated row data. Similar to the replicated
row data, each column is separated by a ‘|’ and
written in ASCII format.
When the spooling program encounters severe
errors (for example, cannot retrieve replicate id for
the replicated row, unable to determine the replicated column’s type, size, or length) or the table
includes UDT columns (whether defined for replication or not), it displays the replicated row data in
hexadecimal format. In this case, the local row data is
not spooled.
BYTE and TEXT Information in RIS Files
When the information recorded in the RIS file includes BYTE or TEXT data, the
RRD information is reported as the following examples show.
Example 1
“<1200, TEXT, PB 877(necromsv) 840338515(00/08/17 20:21:55)>
In this example:
■
1200 is the size of the TEXT data.
■
TEXT is the data type (it is either BYTE or TEXT).
Monitoring and Troubleshooting Enterprise Replication 9-11
Changed Column Information in RIS Files
■
PB is the storage type (PB for storage in the tablespace, BB for
blobspace storage).
■
The next two fields are the server identifier and the time stamp for
the column if the conflict-resolution rule is defined for this replicate
and the column is stored in a blobspace.
Example 2
“<500 (NoChange), TEXT, PB 877(necromsv) 840338478(0000/08/17 20:21:18)>
In this example, (NoChange) after 500 indicates the TEXT data has size of 500
but the data has not been changed on the source server. Therefore the data is
not sent from the source server.
Changed Column Information in RIS Files
See “Changed Column Information in ATS Files” on page 9-8.
BLOB and CLOB Information in RIS Files
See “BLOB and CLOB Information in ATS Files” on page 9-8.
UDT Information in RIS Files
See “UDT Information in ATS Files” on page 9-8.
Preventing Memory Queues from Overflowing
In a well-tuned Enterprise Replication system, the send queue and receive
queue should not regularly overflow from memory to disk. However, if the
queues in memory fill, the transaction buffers are written (spooled) to disk.
Spooled transactions consist of transaction records, replicate information, and
row data. Spooled transaction records and replicate information are stored in
the transaction tables and the replicate information tables in a single dbspace.
Spooled row data is stored in one or more sbspaces.
9-12
IBM Informix Dynamic Server Enterprise Replication Guide
Preventing Memory Queues from Overflowing
For more information, see “Setting Up Send and Receive Queue Spool Areas”
on page 4-12.
The following situations can cause Enterprise Replication to spool to disk:
■
Receiving server is down or suspended.
■
Network connection is down.
If the receiving server or network connection is down or suspended,
Enterprise Replication might spool transaction buffers to disk.
To check for a down server or network connection, run cdr list server
on a root server. This command shows all servers and their connection status and state.
For more information, see “Viewing Replication Server Attributes”
on page 7-4 and “cdr list server” on page A-44.
■
Replicate is suspended.
If a replicate is suspended, Enterprise Replication might spool
transaction buffers to disk.
To check for a suspended replicate, run cdr list replicate. This command shows all replicates and their state.
For more information, see “Viewing Replicate Properties” on
page 7-7 and “cdr list replicate” on page A-38.
■
Enterprise Replication is replicating large transactions.
Enterprise Replication is optimized to handle small transactions
efficiently. Very large transactions or batch jobs force Enterprise Replication into an exceptional processing path that results in spooling.
For best results, avoid replicating these types of transactions.
For more information, see “Large Transactions” on page 2-15.
■
Logical log files are too small or too few.
If the logical log files are too small or the number of logical log files
is too few, Enterprise Replication is more likely to spool transaction
buffers to disk.
To increase the size of the logical logs, see the chapter on logical logs
in the IBM Informix Dynamic Server Administrator’s Guide. For more
information on configuring your logical log files for use with Enterprise Replication, see “Logical Log Configuration Guidelines” on
page 4-11.
Monitoring and Troubleshooting Enterprise Replication 9-13
Preventing DDRBLOCK Mode
■
Server is overloaded.
If a server is low on resources, Enterprise Replication might not be
able to hold all transactions replicating from a source server in memory during processing, and the transactions spool to disk.
If this happens, check the system resources; in particular, check disk
speed, RAM, and CPU resources.
Preventing DDRBLOCK Mode
If the database server comes close to overwriting a logical log that Enterprise
Replication has not yet processed (log wrap), Enterprise Replication enters
DDRBLOCK mode. In DDRBLOCK mode, user transactions are blocked and you
see the following error in the message log:
DDR Log Snooping - DDRBLOCK phase started, userthreads blocked
Although user transactions are blocked while the server is in DDRBLOCK
mode, Enterprise Replication activity is allowed to continue. During this
time, Enterprise Replication attempts process transactions to advance the
replay position and remove the risk of a log overrun. Enterprise Replication
can usually resolve the cause of the DDRBLOCK state. However, in more
extreme cases, the replay position can be overrun. If the replay position is
overrun the following message appears in the message log file:
WARNING: The replay position was overrun, data may not be
replicated.
If this occurs, you must manually resynchronize the source and target
servers. For more information, see “Resynchronizing Replication Servers” on
page 6-16.
9-14
IBM Informix Dynamic Server Enterprise Replication Guide
Preventing DDRBLOCK Mode
DDRBLOCK mode is usually caused by the logical logs being misconfigured
for the current transaction activity or by the Enterprise Replication system
having to spool more than usual. More-than-usual spooling could be caused
by one of the following situations:
■
A one-time job might be larger than normal and thus require more
log space.
■
If one of the target servers is currently unavailable, more spooling of
replicated transactions can be required.
■
The spool file or paging space could be full and needs to be
expanded. For more information, see “Preventing Memory Queues
from Overflowing” on page 9-12.
If Enterprise Replication detects that the log files are configured too small for
the current database activity, then the following message might appear in the
message log file:
Warning - The log space appears to be configured too small for use
with Enterprise Replication (ER). ER may require additional
logical logs to avoid a DDRBLOCK state and/or replay position log
wrap. It is recommended that the logical log configuration be
expanded.
Enterprise Replication can be configured to dynamically add a logical log file
instead of placing the database server in DDRBLOCK mode. Set the
CDR_MAX_DYNAMIC_LOGS configuration parameter to enable Enterprise
Replication to dynamically add a logical log file when the system is in danger
of a log wrap. This allows the system to better adjust to unusual activity. Set
CDR_MAX_DYNAMIC_LOGS to one of the following values:
a positive
number
Enterprise Replication is allowed to dynamically add up to
that number of logical log files.
-1
Enterprise Replication is allowed to dynamically add an
unlimited number of logical log files.
zero
Enterprise Replication does not dynamically add logical log
files, and the system can enter DDRBLOCK mode.
Monitoring and Troubleshooting Enterprise Replication 9-15
Monitoring Disk Usage for Send and Receive Queue Spool
Monitoring Disk Usage for Send and Receive Queue Spool
You should periodically monitor disk usage for the dbspace (specified by
CDR_QHDR_DBSPACE Configuration Parameter configuration parameter)
and the sbspace (CDR_QDATA_SBSPACE Configuration Parameter) that
Enterprise Replication uses to spool the queues to disk.
To check disk usage for:
■
dbspaces
Use onstat -d.
For more information, see the section on monitoring disk usage in
the IBM Informix Dynamic Server Administrator’s Guide and the utilities
chapter of the IBM Informix Administrator’s Reference.
■
sbspaces
Use onstat -d or oncheck -cs,-cS, -ce, -pe, -ps, and -pS.
For more information, see the section on monitoring sbspaces in the
IBM Informix Dynamic Server Performance Guide and the utilities chapter of the IBM Informix Administrator’s Reference.
Tip: When you use onstat -d to monitor disk usage, the S flag in the Flags column
indicates an sbspace. For each sbspace chunk, the first row displays information about
the whole sbspace and user-data area. The second row displays information about the
metadata area.
Increasing the Sizes of Storage Spaces
If you notice that the Enterprise Replication dbspace or sbspace is running
out of disk space, you can increase the size of the space by adding chunks to
the space.
To add a chunk to a dbspace, use onspaces -a. For example, to add a 110
kilobyte chunk with an offset of 0 to the er_dbspace dbspace, enter:
onspaces -a er_dbspace -p /dev/raw_dev2 -o 0 -s 110
To add a chunk to an sbspace, use the same onspaces command above,
however you can specify more information about the chunk that you are
adding. After you add a chunk to the sbspace, you must perform a level-0
backup of the root dbspace and the sbspace.
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IBM Informix Dynamic Server Enterprise Replication Guide
Recovering when Storage Spaces Fill
For more information, see the sections on adding chunks to dbspaces and
sbspaces in the IBM Informix Extended Parallel Server Administrator’s Guide and
the utilities chapter of the IBM Informix Administrator’s Reference.
Recovering when Storage Spaces Fill
When the Enterprise Replication dbspace runs out of disk space, Enterprise
Replication raises an alarm and writes a message to the log. When the
sbspace runs out of disk space, Enterprise Replication hangs. In either case,
you must resolve the problem that is causing Enterprise Replication to spool
(“Preventing Memory Queues from Overflowing” on page 9-12) or you must
allocate additional disk space (“Increasing the Sizes of Storage Spaces” on
page 9-16) before you can continue replication.
Solving Common Configuration Problems
If you experience problems setting up Enterprise Replication, check the
following:
■
Make sure that you created an sbspace for the row data and set the
CDR_QDATA_SBSPACE in the ONCONFIG file.
For more information, see “Setting Up Send and Receive Queue
Spool Areas” on page 4-12 and “CDR_QDATA_SBSPACE Configuration Parameter” on page B-11.
■
Verify that the trusted environment is set up correctly.
For more information, see “Setting Up the Trusted Environment” on
page 4-5.
■
Verify that your SQLHOSTS file is set up properly on each server
participating in replication. You must set up database server groups
in the SQLHOSTS file.
For more information, see “Verifying SQLHOSTS” on page 4-5.
Monitoring and Troubleshooting Enterprise Replication 9-17
Solving Common Configuration Problems
■
Verify the format of the SQLHOSTS file.
The network connection (not the shared memory connection) entry
should appear immediately after the database server group definition. If the network connection does not appear immediately after
the database server group definition, you might see the following
error when you run cdr define server:
command failed -- unable to connect to server specified
(5)
You might also see a message like the following in the message log
for the target server:
Reason: ASF connect error (-25592)
■
Make sure that the unique identifier for each database server (i= in
the options field of the SQLHOSTS information) is consistent across
all nodes in the enterprise.
For more information, see “Database Server Groups on UNIX” on
page 4-6 and Appendix F, “SQLHOSTS Registry Key.”
■
Verify that the operating system times of the database servers that
participate in the replicate are synchronized.
For more information, see “Time Synchronization” on page 2-17.
■
Make sure that the database server has adequate logical log disk
space. If the database server does not have enough logical log space
at initialization, you will see the following error:
command failed -- fatal server error (100)
■
Check the $INFORMIXDIR/etc/buildsmi.xxx files to see if a problem
occurred when the databases server built the SMI tables.
■
Make sure that the databases on all database server instances
involved in replication are set to logging (unbuffered logging is
recommended).
For more information, see “Unbuffered Logging” on page 2-10.
■
For replicates that use any conflict-resolution rule except ignore,
make sure that you define shadow columns (CRCOLS) for each table
involved in replication.
For more information, see “Preparing Tables for Conflict Resolution”
on page 4-25.
9-18
IBM Informix Dynamic Server Enterprise Replication Guide
Solving Common Configuration Problems
■
If you defined a participant using SELECT * from table_name, make
sure that the tables are identical on all database servers defined for
the replicate.
For more information, see “Defining Participants” on page 6-8 and
“Participant Type” on page A-89.
■
Verify that each replicated column in a table on the source database
server has the same data type as the corresponding column on the
target server.
Enterprise Replication does not support replicating a column with
one data type to a column on another database server with a different
data type.
The exception to this rule is cross-replication between simple large
objects and smart large objects.
For more information, see “Enterprise Replication Data Types” on
page 2-19.
■
Verify that all tables defined in a replicate have one PRIMARY KEY
constraint.
For more information, see “Primary Key Constraint” on page 2-11,
the IBM Informix Database Design and Implementation Guide and
IBM Informix Guide to SQL: Syntax.
■
If HDR is enabled in the replication system, then all row data
sbspaces must be created with logging by using the -Df
LOGGING=ON option of the onspaces command.
For more information, see “Row Data sbspaces” on page 4-14 and the
IBM Informix Dynamic Server Administrator’s Guide.
Monitoring and Troubleshooting Enterprise Replication 9-19
Enterprise Replication Event Alarms
Enterprise Replication Event Alarms
The following table describes the alarms that are raised by Enterprise Replication and the events that trigger the alarms. For more information on
handling event alarms, see the appendix on event alarms in the IBM Informix
Administrator’s Reference.
Situation
Level
Message
Snoopy receives a bad buffer
during a log read
ALRM_EMERGENCY
Log corruption detected or read error
occurred while snooping logs.
Snoopy sets DDRBLOCK
(“Preventing DDRBLOCK Mode”
on page 9-14)
ALRM_ATTENTION
DDR Log Snooping - Catchup phase
started, userthreads blocked
Snoopy unsets DDRBLOCK
(“Preventing DDRBLOCK Mode”
on page 9-14)
ALRM_ATTENTION
DDR Log Snooping - Catchup phase
completed, userthreads unblocked
Snoopy detects that the replay
position has been overwritten
(page 9-14)
ALRM_EMERGENCY
WARNING: The replay position was
overrun, data may not be replicated.
An RQM queue runs out of room
to spool (“Recovering when
Storage Spaces Fill” on page 9-17)
ALRM_EMERGENCY
CDR QUEUER: Send Queue space is FULL
- waiting for space in sbspace_name.
RQM cannot find the replicate in
the global catalog for which it has
a transaction
ALRM_ATTENTION
CDR CDR_subcomponent_name: bad
replicate ID replicate_id
Unable to allocate memory when
analyzing opaque UDTs in
collections/rows
ALRM_INFO
CDR CDR_subcomponent_name memory
allocation failed (reason).
Datasync received transaction that
was aborted in first buffer, so there
is nothing to spool to ATS/RIS
ALRM_INFO
Received aborted transaction, no
data to spool.
(1 of 2)
9-20
IBM Informix Dynamic Server Enterprise Replication Guide
Enterprise Replication Event Alarms
Situation
Level
Message
Grouper was unable to apply an
undo (rollback to savepoint) to a
transaction
ALRM_ATTENTION
CDR CDR_subcomponent_name: Could not
apply undo properly. SKIPPING
TRANSACTION.
TX Begin Time: datetime
TX Restart Log Id: log_id
TX Restart Log Position:
log_position
TX Commit Time: datetime
TX End Log Id: log_id
TX End Log Position: log_position
Grouper evaluator is aborting
ALRM_EMERGENCY
CDR Grouper Evaluator thread is
aborting.
Grouper fanout is aborting
ALRM_EMERGENCY
CDR Grouper FanOut thread is
aborting.
Grouper paging sbspace has run
out of space (“Increasing the Sizes
of Storage Spaces” on page 9-16)
ALRM_EMERGENCY
CDR DS thread_name thread is
aborting.
Datasync is aborting
ALRM_ATTENTION
CDR Pager: Paging File full: Waiting
for additional space in sbspace_type
Could not drop delete table while
deleting the replicate from the
local participant.
ALRM_ATTENTION
CDR: Could not drop delete table.
SQL code sql_error_code, ISAM code
isam_error_code.
Table 'database_name:table_name'.
Please drop the table manually.
Grouper is unable to copy the
transaction into send queue.
ALRM_EMERGENCY
CDR: Could not copy transaction at
log id log_unique_id> position
log_position. Skipped.
Grouper detected paging error.
ALRM_EMERGENCY
CDR: Paging error detected.
(2 of 2)
Monitoring and Troubleshooting Enterprise Replication 9-21
Appendix A
Command-Line Utility Reference
Appendix B
Configuration Parameter and Environment Variable
Reference
Appendix C
onstat Command Reference
Appendix D
SMI Table Reference
Appendix E
Replication Examples
Appendix F
SQLHOSTS Registry Key
Appendix G
Notices
Section III
Appendixes
Appendix
Command-Line Utility
Reference
The command-line utility (CLU) lets you configure and control
Enterprise Replication from the command line on your UNIX or
Windows operating system.
This appendix covers the following topics:
■
Command Summary
■
Command Syntax
■
Interpreting the Command-Line Utility Syntax
A
Command Summary
The following table shows the commands and the page where the command
is documented.
Command
Page
cdr change replicate
A-4
cdr change replicateset
A-6
cdr connect server
A-9
cdr define replicate
A-10
cdr define replicateset
A-16
cdr define server
A-19
cdr delete replicate
A-24
cdr delete replicateset
A-26
cdr delete server
A-28
cdr disconnect server
A-32
cdr error
A-34
cdr finderr
A-37
cdr list replicate
A-38
cdr list replicateset
A-42
cdr list server
A-44
cdr modify replicate
A-48
cdr modify replicateset
A-53
cdr modify server
A-55
cdr remove
A-58
cdr resume replicate
A-59
(1 of 2)
A-2 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
Command
Page
cdr resume replicateset
A-61
cdr resume server
A-63
cdr start
A-65
cdr start replicate
A-67
cdr start replicateset
A-69
cdr stop
A-71
cdr stop replicate
A-73
cdr stop replicateset
A-75
cdr suspend replicate
A-77
cdr suspend replicateset
A-79
cdr suspend server
A-81
(2 of 2)
Command Syntax
The next sections show the syntax for all the variations of the cdr commands.
Command-Line Utility Reference A-3
Command Syntax
cdr change replicate
The cdr change replicate command allows you to modify an existing
replicate by adding or deleting one or more participants.
Syntax
-- add
cdr change replicate
Connect Option
p. A-87
Element
modifier
participant
replicate
replicate
-- delete
participant
replicate
Purpose
Specifies the rows and columns
to replicate
Restrictions
See “Considerations for the
SELECT Statement” on
page A-91.
Specifies the database server and The participant must exist.
table for replication
Name of the replicate to change The replicate must exist.
modifier
participant
Syntax
“Participant
Modifier” on
page A-90
“Participant” on
page A-88
“Long Identifiers”
on page A-86
The following table describes the options to cdr change replicate.
Options
Long Form
Short Form
Meaning
--add
-a
Add participants to a replicate.
--delete
-d
Remove participants from a replicate.
A-4 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
Usage
Use this command to add or delete a participant from a replicate. You can
define a replicate that has zero or one participants, but to be useful, a replicate
must have at least two participants.
Important: You cannot start and stop replicates that have no participants.
Important: Enterprise Replication adds the participant to the replicate in an inactive
state, regardless of the state of the replicate. To activate the new participant, run cdr
start replicate with the name of the server group. See “cdr start replicate” on
page A-67.
Examples
The following example adds two participants to the replicate named repl_1:
db1@server1:antonio.table with the modifier select * from table1, and
db2@server2:carlo.table2 with the modifier select * from table2:
cdr change repl -a repl_1 \
“db1@server1:antonio.table1” “select * from table1” \
“db2@server2:carlo.table2” “select * from table2”
The following example removes the same two participants from replicate
repl_1:
cdr change repl -d repl_1 \
“db1@server1:antonio.table1” \
“db2@server2:carlo.table2”
See Also
■
“cdr define replicate” on page A-10
■
“cdr delete replicate” on page A-24
■
“cdr list replicate” on page A-38
■
“cdr modify replicate” on page A-48
■
“cdr resume replicate” on page A-59
■
“cdr start replicate” on page A-67
■
“cdr stop replicate” on page A-73
■
“cdr suspend replicate” on page A-77
Command-Line Utility Reference A-5
Command Syntax
cdr change replicateset
The cdr change replicateset (or cdr change replset) command changes a
replicate set by adding or deleting replicates.
Syntax
-- add
cdr change replicateset
Connect Option
p. A-87
Element
repl_set
replicate
Purpose
Name of the replicate set to
change
Name of the replicates to add to
or delete from the set
repl_set
replicate
-- delete
Restrictions
The replicate set must exist.
The replicates must exist.
Syntax
“Long Identifiers”
on page A-86
“Long Identifiers”
on page A-86
The following table describes the options to cdr change replicateset
Options
Long Form
Short Form
Meaning
--add
-a
Add replicates to a replicate set.
--delete
-d
Remove replicates from a replicate set.
A-6 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
Usage
Use this command to add replicates to a replicate set or to remove replicates
from an exclusive or non-exclusive replicate set:
■
If you add a replicate to an exclusive replicate set, Enterprise Replication changes the existing state and replication frequency settings of
the replicate to the current properties of the exclusive replicate set.
If you remove a replicate from an exclusive replicate set, the replicate
retains the properties of the replicate set at the time of removal (not
the state the replicate was in when it joined the exclusive replicate
set).
When you add or remove a replicate from an exclusive replicate set
that is suspended or that is defined with a frequency interval, Enterprise Replication transmits all the data in the queue for the replicates
in the replicate set up to the point when you added or removed the
replicate. For more information, see “Suspending a Replicate Set” on
page 8-7 and “Frequency Options” on page A-92
■
If you add or remove a replicate to a non-e.xclusive replicate set, the
replicate retains its individual state and replication frequency
settings.
Examples
The following example adds the replicates house and barn to replicate set
building_set:
cdr change replicateset -add building_set house barn
The following example removes the replicates teepee and wigwam from
replicate set favorite_set:
cdr cha replset -del favorite_set teepee wigwam
See Also
■
“cdr define replicate” on page A-10
■
“cdr delete replicateset” on page A-26
■
“cdr list replicateset” on page A-42
■
“cdr modify replicateset” on page A-53
Command-Line Utility Reference A-7
Command Syntax
■
“cdr resume replicateset” on page A-61
■
“cdr start replicateset” on page A-69
■
“cdr stop replicateset” on page A-75
■
“cdr suspend replicateset” on page A-79
A-8 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
cdr connect server
The cdr connect server command reestablishes a connection to a database
server that has been disconnected with a cdr disconnect server command.
Syntax
server_ group
cdr connect server
Connect Option
p. A-87
Element
server_group
Purpose
Name of database server group
to resume
Restrictions
Syntax
The database server group must
be defined for replication and be
disconnected.
Usage
The cdr connect server command reestablishes a connection to the server
server_group.
See Also
■
“cdr define server” on page A-19
■
“cdr delete server” on page A-28
■
“cdr disconnect server” on page A-32
■
“cdr list server” on page A-44
■
“cdr modify server” on page A-55
■
“cdr resume server” on page A-63
■
“cdr suspend server” on page A-81
Command-Line Utility Reference A-9
Command Syntax
cdr define replicate
The cdr define replicate command defines a replicate in the global catalog.
Syntax
Conflict Options
p. A-11
cdr define replicate
Connect Option
p. A-87
Scope Options
p. A-11
Element
modifier
Purpose
Specifies the rows and columns
to replicate
participant
Name of a participant in the
replication
Name of the new replicate
replicate
replicate
participant
Frequency Options
p. A-92
Restrictions
See “Considerations for the
SELECT Statement” on
page A-91.
The participant must exist.
The replicate name must be
unique.
modifier
Special Options
p. A-13
Syntax
“Participant
Modifier” on
page A-90
“Participant” on
page A-88
“Long Identifiers”
on page A-86
Usage
To be useful, a replicate must include at least two participants. You can define
a replicate that has only one participant, but before you can use that replicate,
you must use cdr change replicate to add more participants.
Important: You cannot start and stop replicates that have no participants.
When you define a replicate, the replicate does not begin until you explicitly
change its state to active. For more information, see “cdr start replicate” on
page A-67.
A-10 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
Important: Do not create more than one replicate definition for each row and column
set of data to replicate. If the participant is the same, Enterprise Replication attempts
to insert duplicate values during replication.
Conflict Options
The conflict options specify how Enterprise Replication should resolve
conflicts with data arriving at the database server.
Conflict Options
Back to cdr define replicate p. A-10
Back to cdr modify replicate p. A-48
-- conflict =
ignore
SPL_routine
-- optimize
timestamp
,
SPL_routine
-- optimize
Element
SPL_routine
Purpose
SPL routine for conflict
resolution
Restrictions
The SPL routine must exist.
Syntax
“Long Identifiers”
on page A-86
Scope Options
The scope options specify how Enterprise Replication should handle
problems with data arriving at the database server.
Scope Options
-- scope =
Back to cdr define replicate p. A-10
Back to cdr modify replicate p. A-48
row
transaction
Command-Line Utility Reference A-11
Command Syntax
For more information, see “Conflict Resolution” on page 3-10.
The following table describes the conflict and scope options.
Options
Long Form
Short Form
Meaning
--conflict=
-C
Specifies the rule that will be used for conflict
resolution. The action that Enterprise Replication
takes depends upon the scope.
--optimize
-O
Specifies that the SPL routine is optimized.
An optimized SPL routine is called only when a
collision is detected and the row to be replicated
meets the following two conditions:
■
It is from the same database server that last
updated the local row on the target table.
■
It has a time stamp greater than or equal to that of
the local row.
When this option is not present, Enterprise Replication always calls the SPL routine defined for the
replicate when a conflict is detected.
--scope=
-S=
Specifies the scope that will be invoked when Enterprise Replication encounters a problem with data or
a conflict occurs.
For more information, see “Scope” on page 3-17.
If scope is not specified, the default scope is
transaction.
When specifying the scope, you can abbreviate transaction to tra.
A-12 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
Special Options
Special Options
Back to cdr define replicate
p. A-10
1
-- ats
1
-- ris
1
-- floatieee
1
-- floatcanon
1
1
-- firetrigger
--fullrow
y
n
The following table describes the special options to cdr define replicate.
Options
Long Form
Short Form
Meaning
--ats
-A
Activates aborted transaction spooling for
replicate transactions that fail to be applied to
the target database. For more information, see
“Setting Up Error Logging” on page 6-11 and
Chapter 9, “Monitoring and Troubleshooting
Enterprise Replication.”
--ris
-R
Activates row-information spooling for
replicate row data that fails conflict resolution
or encounters replication order problems. For
more information, see “Setting Up Error
Logging” on page 6-11 and Chapter 9,
“Monitoring and Troubleshooting Enterprise
Replication.”
(1 of 2)
Command-Line Utility Reference A-13
Command Syntax
Options
Long Form
Short Form
Meaning
--fullrow y | n
-f y | n
Specifies to (y) replicate the full row and enable
upserts or (n) replicate only changed columns
and disable upserts. By default, Enterprise
Replication always replicates the entire row
and enables upserts. For more information, see
“Replicating Only Changed Columns” on
page 6-11.
--floatieee
-I
Transfers replicated floating-point numbers in
in either 32-bit (for SMALLFLOAT) or 64-bit
(for FLOAT) IEEE floating-point format. Use
this option for all new replicate definitions. For
more information, see “Using the IEEE Floating
Point or Canonical Format” on page 6-13.
--floatcanon
-F
Transfers replicated floating-point numbers in
machine-independent decimal representation.
This format is portable, but can lose accuracy.
This format is provided for backwardcompatibility only; use --floatieee for all new
replicate definitions. For more information, see
“Using the IEEE Floating Point or Canonical
Format” on page 6-13.
--firetrigger
-T
Specifies that the rows that this replicate inserts
fire triggers at the destination. For more information, see “Enabling Triggers” on page 6-14.
(2 of 2)
Examples
The following example illustrates the use of cdr define replicate:
1
2
3
4
cdr define repl --conflict=timestamp,sp1 \
--scope=tran --ats --fullrow n --floatieee newrepl \
“db1@iowa:antonio.table1” “select * from table1” \
“db2@utah:carlo.table2” “select * from table2”
A-14 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
Line 1 of the example specifies a primary conflict-resolution rule of timestamp.
If the primary rule fails, the SPL routine sp1 will be invoked to resolve the
conflict. Because no database server is specified here (or on any later line), the
command connects to the database server named in the INFORMIXSERVER
environment variable.
Line 2 specifies that the replicate has a transaction scope for conflictresolution scope and enables aborted transaction spooling. Enterprise Replication will only replicate the rows that changed and uses the IEEE floating
point format to send floating-point numbers across dissimilar platforms. The
final item specifies the name of the replicate, newrepl.
Line 3 defines the first participant, “db1@iowa:antonio.table1”, with the
select statement “select * from table1”.
Line 4 defines a second participant, “db2@utah:carlo.table2”, with the
select statement “select * from table2”.
The next example is the same as the preceding example with the following
exceptions:
Line 1 instructs Enterprise Replication to use the global catalog on database
server ohio. Line 2 also specifies that the data should be replicated every five
hours.
1
2
3
4
cdr def repl -c ohio -C timestamp,sp1 \
-S tran -A -e 5:00 -I newrepl \
“db1@iowa:antonio.table1” “select * from table1” \
“db2@utah:carlo.table2” “select * from table2”
See Also
■
“cdr change replicate” on page A-4
■
“cdr delete replicate” on page A-24
■
“cdr list replicate” on page A-38
■
“cdr modify replicate” on page A-48
■
“cdr resume replicate” on page A-59
■
“cdr start replicate” on page A-67
■
“cdr stop replicate” on page A-73
■
“cdr suspend replicate” on page A-77
Command-Line Utility Reference A-15
Command Syntax
cdr define replicateset
The cdr define replicateset (or cdr define replset) command defines a
replicate set. A replicate set is a collection of several replicates to be managed
together.
Important: Enterprise Replication supports replicate sets for IBM Informix Dynamic
Server, Version 9.3, and later only. You cannot define or modify replicate sets to
include replicates with participants that are Version 9.2 and earlier. In addition,
replicate sets are different from and are incompatible with replicate groups (in
Version 9.2 and earlier).
Syntax
cdr define replicateset
repl_ set
1
replicate
Connect Option
p. A-87
-- exclusive
1
Frequency Options
p. A-92
Element
repl_set
Purpose
Name of replicate set to create
replicate
Name of a replicate to be
included in the replicate set
Restrictions
The name must be unique and
cannot be the same as a replicate
name.
The replicate must exist.
A-16 IBM Informix Dynamic Server Enterprise Replication Guide
Syntax
“Long Identifiers”
on page A-86
“Long Identifiers”
on page A-86
Command Syntax
The following table describes the option to cdr define replicateset.
Options
Long Form
Short Form
Meaning
--exclusive
-X
Creates an exclusive replicate set. For
more information, see “Exclusive
Replicate Sets” on page 8-4.
Usage
Use the cdr define replicateset command to define a replicate set.
Any valid replicate can be defined as part of a replicate set. A replicate can
belong to more than one non-exclusive replicate set, but to only one exclusive
replicate set. For details on the differences between exclusive and nonexclusive replicate sets, see “Creating Replicate Sets” on page 8-4.
When you create an exclusive replicate set, the state is initially set to active.
For more information, see “Displaying Information About Replicates” on
page A-40).
To create an exclusive replicate set and set the state to inactive
1.
Create an empty replicate set.
2.
Stop the replicate set.
3.
Add replicates to the replicate set.
4.
Set the state of the replicate set to active by running cdr start
replicateset.
Because individual replicates in a non-exclusive replicate set can have
different states, the non-exclusive replicate set itself has no state.
Important: Once you create an exclusive replicate set, you cannot change it to nonexclusive, and vice versa.
Command-Line Utility Reference A-17
Command Syntax
Example
The following example connects to the default server and defines the nonexclusive replicate set accounts_set with replicate participants repl1, repl2,
and repl3:
cdr def replset accounts_set repl1 repl2 repl3
The following example connects to the server olive and defines the exclusive
replicate set market_set with replicate participants basil and thyme:
cdr def replset --connect=olive --exclusive market_set basil thyme
See Also
■
“cdr change replicateset” on page A-6
■
“cdr delete replicateset” on page A-26
■
“cdr list replicateset” on page A-42
■
“cdr modify replicateset” on page A-53
■
“cdr resume replicateset” on page A-61
■
“cdr start replicateset” on page A-69
■
“cdr stop replicateset” on page A-75
■
“cdr suspend replicateset” on page A-79
A-18 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
cdr define server
The cdr define server command defines a database server group and all its
members (that is, all database servers that are members of the database server
group) for Enterprise Replication.
Syntax
Options
p. A-21
cdr define server
-- connect server_ group
-- init
-- nonroot
server_ group
-- sync=sync_server
-- leaf
Element
server_group
Purpose
Name of a database server group
to declare for Enterprise
Replication
sync_server
Name of server to use for
synchronization for all subsequent server definitions to an
existing replication system
Restrictions
Syntax
Must be the name of an existing
database server group in
SQLHOSTS. See “Setting up
Database Server Groups” on
page 4-5.
Must be a server that is registered “Long Identifiers”
with Enterprise Replication. The on page A-86
server must be online.
Command-Line Utility Reference A-19
Command Syntax
The following table describes the long forms shown in the syntax diagram.
Options
Long Form
Short Form
Meaning
--connect
-c
Connects to the database server that is
being defined. If this option is omitted,
$INFORMIXSERVER must be set to
server_group.
--init
-I
Adds server_group to the replication system.
The server_group must be the same as the
connection server.
--leaf
-L
Defines the server as a leaf server. If neither
leaf nor nonroot is specified, the server is
defined as a root server.
--nonroot
-N
Defines the server as a nonroot server. If
neither leaf nor nonroot is specified, the
server is defined as a root server.
--sync=sync_server
-S=sync_server Uses the global catalog on sync_server as the
template for the global catalog on the new
replication server, server_group.
Use this option for adding subsequent
server_groups to an existing replication
system.
For Hierarchical Routing (HR) topologies,
Enterprise Replication also uses the
sync_server as the new server’s parent in the
current topology.
Usage
The cdr define server command creates the Enterprise Replication global
catalog and adds the database server from the server_group.
A-20 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
Options
The options allow you to modify the default behavior of cdr define server.
Options
Back to cdr define server
p. A-19
-- ats = ats _ dir
-- ris = ris _ dir
-- idle = timeout
Element
ats_dir
Purpose
Name of the directory for
Aborted Transaction Spooling
ris_dir
Name of the directory for Row
Information Spooling
timeout
Idle timeout for this replication
server
Restrictions
Must be a full pathname. The
path for the directory can be no
longer than 256 bytes.
Must be a full pathname. The
path for the directory can be no
longer than 256 characters.
Must be an integer number of
minutes. 0 indicates no timeout.
The maximum value is 32,767.
Syntax
Follows naming
conventions on your
operating system
Follows naming
conventions on your
operating system
Integer
Command-Line Utility Reference A-21
Command Syntax
The following table describes the options to cdr define server.
Options
Long Form
Short Form
Meaning
--ats=ats_dir
-A=ats_dir
Activates aborted transaction spooling
for replicate transactions that fail to be
applied to the target database. For more
information, see Chapter 9, “Monitoring
and Troubleshooting Enterprise
Replication.”
--ris=ris_dir
-R=ris_dir
Activates row information spooling for
replicate row data that fails conflict
resolution or encounters replicationorder problems. For more information,
see Chapter 9, “Monitoring and Troubleshooting Enterprise Replication.”
--idle=timeout
-i=timeout
Causes an inactive connection to be
terminated after timeout minutes. If timeout is 0, the connection does not time out.
The default value is 0.
Examples
The first example defines the first database server in a replication
environment. The command connects to the database server stan, initializes
Enterprise Replication, and sets the idle time-out to 500 minutes. The
example also specifies that any files that ATS generates will go into the
/cdr/ats directory.
cdr define server --connect=stan --idle=500 --ats /cdr/ats \
--init g_stan
A-22 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
The following example adds a database server to the replication environment
in the first example. The command connects to the database server oliver,
initializes Enterprise Replication, synchronizes its catalogs with the catalogs
on the existing database server stan, and defines the database server oliver
with an idle time-out of 600 minutes. This command also specifies that any
files that ATS generates will go into the /cdr/ats directory.
cdr define server -c oliver -i 600 -A /cdr/ats -I -S \
g_stan g_oliver
See Also
■
“cdr connect server” on page A-9
■
“cdr delete server” on page A-28
■
“cdr disconnect server” on page A-32
■
“cdr list server” on page A-44
■
“cdr modify server” on page A-55
■
“cdr resume server” on page A-63
■
“cdr suspend server” on page A-81
Command-Line Utility Reference A-23
Command Syntax
cdr delete replicate
The cdr delete replicate command deletes a replicate from the global catalog.
Syntax
repl_ name
cdr delete replicate
Connect Option
p. A-87
Element
repl_name
Purpose
Name of the replicate to delete
Restrictions
The replicate must exist.
Syntax
“Long Identifiers”
on page A-86
Usage
The cdr delete replicate command deletes the replicate repl_name from the
global catalog. All replication data for the replicate is purged from the send
queue at all participating database servers.
Warning: Avoid deleting a replicate and immediately re-creating it with the same
name. If you re-create the objects immediately (before the operation finishes propagating to the other Enterprise Replication database servers in the network), failures
might occur in the Enterprise Replication system at the time of the operation or later.
For more information, see “Operational Considerations” on page 2-8.
Example
The following command connects to the default database server specified by
$INFORMIXSERVER and deletes the replicate smile:
cdr del rep smile
A-24 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
See Also
■
“cdr change replicate” on page A-4
■
“cdr define replicate” on page A-10
■
“cdr list replicate” on page A-38
■
“cdr modify replicate” on page A-48
■
“cdr resume replicate” on page A-59
■
“cdr start replicate” on page A-67
■
“cdr stop replicate” on page A-73
■
“cdr suspend replicate” on page A-77
Command-Line Utility Reference A-25
Command Syntax
cdr delete replicateset
The cdr delete replicateset (or cdr delete replset) command deletes a
replicate set.
Syntax
repl_ set
cdr delete replicateset
Connect Option
p. A-87
Element
repl_set
Purpose
Name of replicate set to delete
Restrictions
The replicate set must exist.
Syntax
“Long Identifiers”
on page A-86
Usage
The cdr delete replicateset command deletes the exclusive or non-exclusive
replicate set repl_set from the global catalog.
The cdr delete replicateset command does not affect the replicates or
associated data. When a replicate set is deleted, the individual replicates
within the replicate set are unchanged.
Warning: Do not delete time-based exclusive replicate sets. Doing so might result in
inconsistent data.
Warning: Avoid deleting a replicate set and immediately re-creating it with the same
name. If you re-create the objects immediately (before the operation finishes propagating to the other Enterprise Replication database servers in the network), failures
might occur in the Enterprise Replication system at the time of the operation or later.
For more information, see “Operational Considerations” on page 2-8.
A-26 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
Example
The following example connects to the default database server and deletes
the replicate set accounts_set:
cdr del replset accounts_set
See Also
■
“cdr change replicateset” on page A-6
■
“cdr define replicate” on page A-10
■
“cdr list replicateset” on page A-42
■
“cdr modify replicateset” on page A-53
■
“cdr resume replicateset” on page A-61
■
“cdr start replicateset” on page A-69
■
“cdr stop replicateset” on page A-75
■
“cdr suspend replicateset” on page A-79
Command-Line Utility Reference A-27
Command Syntax
cdr delete server
The cdr delete server command deletes a database server from the global
catalog.
Syntax
server _ group
cdr delete server
Connect Option
p. A-87
Element
server_group
Purpose
Restrictions
Name of database server group The database server group must
to remove from the global catalog be currently defined in Enterprise Replication.
Syntax
Usage
The cdr delete server command deletes the database server in server_group
from the global catalog, removes the database server from all participating
replicates, and purges all replication data from the send queues for the
specified database server. The command shuts down Enterprise Replication
on the database server and removes the global catalog from the database
server.
When you delete an Enterprise Replication server, you must issue the cdr
delete server command twice: once on the server being deleted and once on
another server in the enterprise. The first cdr delete server removes the
Enterprise Replication server from the local global catalog and removes the
Enterprise Replication connection to other hosts. The second cdr delete
server removes the Enterprise Replication server from the other replication
servers in the system. For more information, see the “Examples” on
page A-29.
A-28 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
You can issue the cdr delete server command from any replication server.
The only limitation is that you cannot delete a server with children. You must
delete the children of a server before deleting the parent server.
You cannot delete a server from the enterprise if it is stopped. To delete a
server with cdr delete server, you must issue a cdr start command first.
Warning: Avoid deleting a replication server and immediately re-creating it with the
same name. If you re-create the objects immediately (before the operation finishes
propagating to the other Enterprise Replication database servers in the network),
failures might occur in the Enterprise Replication system at the time of the operation
or later. For more information, see “Operational Considerations” on page 2-8.
Examples
This example removes the server g_italy from the replication environment.
(assume that you issue the commands from the replication server g_usa):
cdr delete server g_italy
cdr delete server -c italy g_italy
The first command performs the following actions:
■
Removes g_italy from the usa global catalog
■
Drops the connection from g_usa to g_italy
■
Removes g_italy from all participating replicates
■
Purges the replication data destined for g_italy from send queues
■
Broadcasts this delete server command to all other servers (other
than g_italy) so that they can perform the same actions
The second command connects to server italy, and removes Enterprise Replication from italy. That is, it removes the syscdr database and removes or
stops other components of Enterprise Replication.
Command-Line Utility Reference A-29
Command Syntax
Figure A-1 shows a replication environment with three replication servers,
g_usa, g_italy, and g_japan.
Figure A-1
Three Replication Servers
g_italy
g_usa
g_japan
To remove Enterprise Replication from this environment, issue the following
commands from the computer where the usa replication server resides.
To remove Enterprise Replication from this environment
1.
Run:
cdr delete server g_italy
This command removes connections between the italy replication
server and all other servers in the replication system (usa and japan)
and removes any queued data.
2.
Run:
cdr delete server -c italy g_italy
This command removes all replication information (including the
syscdr database) from the italy database server.
3.
Run:
cdr delete server g_japan
cdr delete server -c g_japan
These commands remove the japan replication server.
4.
Run:
cdr delete server g_usa
This command removes the replication information from the usa
replication server itself.
A-30 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
See Also
■
“cdr connect server” on page A-9
■
“cdr define server” on page A-19
■
“cdr disconnect server” on page A-32
■
“cdr list server” on page A-44
■
“cdr modify server” on page A-55
■
“cdr resume server” on page A-63
■
“cdr suspend server” on page A-81
Command-Line Utility Reference A-31
Command Syntax
cdr disconnect server
The cdr disconnect server command stops a server connection.
Syntax
server _ group
cdr disconnect server
Connect Option
p. A-87
Element
server_group
Purpose
Name of the database server
group to disconnect
Restrictions
The database server group must
be currently active in Enterprise
Replication.
Syntax
Usage
The cdr disconnect server command drops the connection (for example, for
a dialup line) between server_group and the server specified in the --connect
option. If the --connect option is omitted, the command drops the connection
between server_group and the default database server ($INFORMIXSERVER).
Example
The following example drops the connection between the default database
server ($INFORMIXSERVER) and the server group g_store1:
cdr disconnect server g_store1
See Also
■
“cdr connect server” on page A-9
■
“cdr define server” on page A-19
■
“cdr delete server” on page A-28
■
“cdr list server” on page A-44
A-32 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
■
“cdr modify server” on page A-55
■
“cdr resume server” on page A-63
■
“cdr suspend server” on page A-81
Command-Line Utility Reference A-33
Command Syntax
cdr error
The cdr error command manages the error table and provides convenient
displays of errors.
Syntax
cdr error
Connect Option
p. A-87
-- seq = err _ server : seqno
"
-- prune
last
first
"
,
-- zap
-- all =
-- follow
-- all
-- nomark
Element
err_server
first
Purpose
Name of database server group
that holds the error table
Start date for a range
last
Ending date for range
seqno
Sequence number of a specific
error
Restrictions
The server must be registered for
Enterprise Replication.
You must provide a valid date
and time.
You must provide a later date
and time than first.
You must provide the number of
an error in the error table.
A-34 IBM Informix Dynamic Server Enterprise Replication Guide
Syntax
“Long Identifiers” on
page A-86
“Time of Day” on
page A-93
“Time of Day” on
page A-93
Integer
Command Syntax
The following table describes the options to cdr error:
Options
Long Form
Short Form
(no options
specified)
Meaning
Print the current list of errors. After the errors have
been printed, mark them as reviewed. Enterprise
Replication does not display errors marked as
reviewed.
--all
-a
When used with the -move option, move the error
table to dbspace on all defined servers. Otherwise,
print all errors, including those already reviewed.
--follow
-f
Continuously monitor the error table.
--nomark
-n
Do not mark errors as reviewed.
--prune
-p
Prune the error table to those times in the range from
first to last. If first is omitted, then all errors earlier
than last are removed.
--seq
-s
Remove the (single) error specified by server:seqno
from the error table.
--zap
-z
Remove all errors from the error table.
Usage
The cdr error command allows you to examine replication errors on any
replication server. Sometimes a command succeeds on the server on which it
is executed, but fails on one of the remote servers. For example, if you execute
cdr define replicate on server1 but the table name is misspelled on server2,
the command succeeds on server1 and appears to have completed successfully. You can use cdr error -c server2 to see why replication is failing.
The cdr error command also allows you to administer the cdr error table
remotely. The reviewed flag lets you watch for new errors while keeping the
old errors in the table. For example, you could run cdr error periodically and
append the output to a file.
Command-Line Utility Reference A-35
Command Syntax
Examples
The following command displays the current list of errors on database server
hill:
cdr error --connect=hill
After the errors are displayed, Enterprise Replication marks the errors as
reviewed.
The following command connects to the database server lake and removes
from the error table all errors that occurred before the time when the
command was issued:
cdr error -c lake --zap
The following command deletes all errors from the error table that occurred
at or before 2:56 in the afternoon on May 1, 2000:
cdr error -p “2000-05-01 14:56:00”
The following command deletes all errors from the error table that occurred
at or after noon on May 1, 2000 and before or at 2:56 in the afternoon on
May 1, 2000:
cdr error -p “2000-05-01 14:56:00,2000-05-01 12:00:00”
A-36 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
cdr finderr
The cdr finderr command looks up a specific Enterprise Replication error
number and displays the corresponding error text.
Syntax
cdr finderr
Element
error_number
Purpose
Enterprise Replication error
number to look up.
ER_error_number
Restrictions
Must be a positive integer.
Syntax
You can also view the Enterprise Replication error messages in the file
$INFORMIXDIR/incl/esql/cdrerr.h.
Command-Line Utility Reference A-37
Command Syntax
cdr list replicate
The cdr list replicate command displays information about the replicates on
the current server.
Syntax
cdr list replicate
Connect Option
p. A-87
Element
replicate
Purpose
Name of the replicates
brief
replicate
Restrictions
The replicates must exist.
full
Syntax
“Long Identifiers”
on page A-86
Usage
The cdr list replicate command displays information about replicates (the
full option). If no replicates are named, the command lists all replicates on
the current server. If one or more replicates are named, the command
displays detailed information about those replicates.
To display only replicate names and participant information, use the brief
option.
You do not need to be user informix to use this command.
In hierarchical topology, leaf servers have limited information about other
database servers in the Enterprise Replication domain. Therefore, when cdr
list replicate is executed against a leaf server, it displays incomplete information about the other database servers.
A-38 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
Example
The following example displays a list of the replicates on the current server
with full details:
cdr list replicate
The output from the previous command might be the following:
CURRENTLY DEFINED REPLICATES
--------------------------------------------REPLICATE:
Repl1
STATE:
Inactive
CONFLICT:
Ignore
FREQUENCY:
immediate
QUEUE SIZE:
0
PARTICIPANT:
bank:joe.teller
OPTIONS:
row,ris,ats
REPLICATE:
STATE:
CONFLICT:
FREQUENCY:
QUEUE SIZE:
PARTICIPANT:
OPTIONS:
Repl2
Inactive
Ignore
immediate
0
bank:joe.account
row,ris,ats
The following example displays a list of the replicates on the current server
with brief details:
cdr list replicate brief
The output from the previous command might be the following:
REPLICATE
TABLE
SELECT
-----------------------------------------------------------Repl1
bank@g_newyork:joe.teller
select * from
Repl1
bank@g_sanfrancisco:joe.teller
select * from
Repl2
bank@g_portland:joe.teller
select * from
Repl2
bank@g_atlanta:joe.teller
select * from
joe.teller
joe.teller
joe.teller
joe.teller
Command-Line Utility Reference A-39
Command Syntax
Displaying Information About Replicates
The STATE field can include the following values.
Value
Active
Description
Specifies that Enterprise Replication captures data from the logical
log and transmits it to participants
Definition Indicates that the replication definition failed on a peer server
Failed
Inactive
Specifies that no database changes are captured, transmitted, or
processed
Pending
Indicates that a cdr delete replicate command has been issued and
the replicate is waiting for acknowledgement from the participants
Quiescent
Specifies that no database changes are captured for the replicate or
participant
Suspended
Specifies that the replicate captures and accumulates database
changes but does not transmit any of the captured data
The CONFLICT field can include the following values.
Value
Description
Ignore
Specifies that the replicate uses the ignore conflict-resolution
rule
Timestamp
Specifies that the replicate uses the time stamp conflictresolution rule
Procedure
Specifies that the replicate uses an SPL routine as the
conflict-resolution rule
A-40 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
The FREQUENCY field can include the following values.
Value
Description
immediate
Specifies that replication occurs immediately
every hh:mm
Specifies that replications occur at intervals (for example,
13:20 specifies every thirteen hours and 20 minutes)
at day.hh:mm
Specifies that replications occur at a particular time on a
particular day (for example, 15.18:30 specifies on the 15th
day of the month at 6:30 P.M.)
The following example specifies the names of replicate:
cdr list repl Repl1
The following output might result from the previous command:
REPLICATE
TABLE
SELECT
-----------------------------------------------------------Repl1
bank@g_newyork:joe.teller
select * from joe.teller
Repl1
bank@g_sanfrancisco:joe.teller
select * from joe.teller
Repl1
bank@g_portland:joe.teller
select * from joe.teller
See Also
■
“cdr change replicate” on page A-4
■
“cdr define replicate” on page A-10
■
“cdr delete replicate” on page A-24
■
“cdr modify replicate” on page A-48
■
“cdr resume replicate” on page A-59
■
“cdr start replicate” on page A-67
■
“cdr stop replicate” on page A-73
■
“cdr suspend replicate” on page A-77
Command-Line Utility Reference A-41
Command Syntax
cdr list replicateset
The cdr list replicateset (or cdr list replset) command displays information
about the replication sets defined on the current server.
Syntax
cdr list replicateset
Connect Option
p. A-87
Element
repl_set
Purpose
Name of the replicates
Restrictions
The replicates must exist.
repl_set
Syntax
“Long Identifiers”
on page A-86
Usage
The cdr list replicateset command displays a list of the replicate sets that are
currently defined. To list the information about each of the replicates within
the replicate set, use cdr list replicateset repl_set. For more information, see
“Displaying Information About Replicates” on page A-40.
In hierarchical topology, leaf servers have limited information about other
database servers in the Enterprise Replication domain. Therefore, when cdr
list replicateset is executed against a leaf server, it displays incomplete information about the other database servers.
You do not need to be user informix to use this command.
Examples
The following example displays a list of the replicate sets on the current
server:
cdr list replicateset
A-42 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
The following output might result from the previous command:
REPLSET
PARTICIPANTS
-------------------------------------------------g1
[Exclusive]
Repl1, Repl4
g2
Repl2
g3
Repl3
This example displays information for all the replicates in the replicate set
sales_set:
cdr list replset g1
The following output might result from the previous command:
REPLICATE SET:g1 [Exclusive]
CURRENTLY DEFINED REPLICATES
---------------------------------------------------------------------REPLICATE:
Repl1
STATE:
Inactive
CONFLICT:
Ignore
FREQUENCY:
immediate
QUEUE SIZE:
0
PARTICIPANT:
bank:arthur.account
OPTIONS:
row,ris,ats
REPLICATE:
STATE:
CONFLICT:
FREQUENCY:
QUEUE SIZE:
PARTICIPANT:
OPTIONS:
Repl4
Inactive
Ignore
immediate
0
bank:arthur.teller
row,ris,ats
See Also
■
“cdr change replicateset” on page A-6
■
“cdr define replicate” on page A-10
■
“cdr delete replicateset” on page A-26
■
“cdr modify replicateset” on page A-53
■
“cdr resume replicateset” on page A-61
■
“cdr start replicateset” on page A-69
■
“cdr stop replicateset” on page A-75
■
“cdr suspend replicateset” on page A-79
Command-Line Utility Reference A-43
Command Syntax
cdr list server
The cdr list server command displays a list of the Enterprise Replication
servers that are visible to the current server.
Syntax
cdr list server
Connect Option
p. A-87
Element
server_group
Purpose
Name of the server group
server_group
Restrictions
Syntax
The database server groups must
be defined for Enterprise
Replication.
Usage
The cdr list server command displays information about servers. You do not
need to be user informix to use this command.
Listing All Enterprise Replication Servers
When no server-group name is given, the cdr list server command lists all
database server groups that are visible to the current replication server.
In hierarchical topology, leaf servers only have information about their
parent database servers in the Enterprise Replication domain. Therefore,
when cdr list server is executed against a leaf server, it displays incomplete
information about the other database servers.
For example, cdr list server might give the following output:
SERVER
ID STATE
STATUS
QUEUE CONNECTION CHANGED
-------------------------------------------------------------g_newyork
1 Active
Local
0
g_portland
2 Active
Connected 0
Mar 19 13:48:44
g_sanfrancisco 3 Active
Connected 0
Mar 19 13:48:40
A-44 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
The SERVER and ID Columns
The SERVER and ID columns display the name and unique identifier of the
Enterprise Replication server group.
The STATE Column
The STATE column can have the following values.
Active
Indicates that the server is active and replicating data
Deleted
Indicates that the server has been deleted and that it is not
capturing or delivering data and the queues are being drained
Quiescent
Indicates that the server is in the process of being defined
Suspended
Indicates that delivery of replication data to the server is suspended
The STATUS Column
The STATUS column can have the following values.
Connected
Indicates that the server connection is up
Connecting Indicates that the server is attempting to connect
Disconnect Indicates that the server connection is down in response to an
explicit disconnect
Dropped
Indicates that the server connection is down due to a network error
because the server is unavailable
Error
Indicates that an error has occurred (check the log and contact
customer support, if necessary)
Local
Identifies that this server is the local server as opposed to a remote
server
Timeout
Indicates that the connection is down due to an idle timeout
Command-Line Utility Reference A-45
Command Syntax
The QUEUE Column
The QUEUE column displays the size of the queue for the server group.
The CONNECTION CHANGED Column
The CONNECTION CHANGED column displays the most recent time that the
status of the server connection was changed.
Displaying Details about a Single Replication Server
When the cdr list server command includes the name of a database server
group, the command displays the attributes of that database server. For
example, cdr list server g_usa might give the following output:
NAME
ID
ATTRIBUTES
----------------------------------------------------g_usa
3
timeout=15,atsdir=/w/ats risdir=/w/ris
Examples
In Figure A-2 and in the following examples, usa and italy are root servers,
denver and boston are nonroot servers, and miami is a leaf server. The usa
server is the parent of denver and boston, and boston is the parent of miami.
usa
denver
italy
boston
miami
A-46 IBM Informix Dynamic Server Enterprise Replication Guide
Figure A-2
cdr list server
example
Command Syntax
The example is created by running the following commands:
cdr list server g_usa
g_usa
1 timeout=15 hub
cdr list server -c denver g_denver
g_denver 27 root=g_usa
cdr list server -c italy g_denver
g_denver 27 root=g_usa forward=g_usa
cdr list server g_miami
g_miami
4 root=g_boston leaf
See Also
■
“cdr connect server” on page A-9
■
“cdr define server” on page A-19
■
“cdr delete server” on page A-28
■
“cdr disconnect server” on page A-32
■
“cdr modify server” on page A-55
■
“cdr resume server” on page A-63
■
“cdr start” on page A-65
■
“cdr suspend server” on page A-81
Command-Line Utility Reference A-47
Command Syntax
cdr modify replicate
The cdr modify replicate command modifies replicate attributes.
Syntax
cdr modify replicate
replicate
1
Conflict Options
p. A-11
1
Scope Options
p. A-11
1
Frequency
Options p. A-92
Connect Option
p. A-87
participant
Special Options
p. A-50
Element
participant
replicate
Purpose
Name of a participant in the
replication
Name of the replicate to modify
Restrictions
The participant must be a
member of the replicate.
The replicate name must exist.
Syntax
“Participant” on
page A-88
“Long Identifiers”
on page A-86
Usage
The cdr modify replicate command modifies the attributes of a replicate or
of one or more participants in the replicate. You can also change the mode of
a participant. If the command does not specify participants, the changes
apply to all participants in the replicate.
For attribute information, see “cdr define replicate” on page A-10.
To add or delete a participant, see “cdr change replicate” on page A-4.
A-48 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
Important: If you change the conflict-resolution rule with cdr modify replicate,
you must also explicitly state SCOPE parameter, even if the SCOPE value does not
change.
Restrictions
The attributes for cdr modify replicate are the same as the attributes for cdr
define replicate, with the following exceptions:
■
You cannot change the machine-independent decimal representation
(--floatcanon) or IEEE floating point (--floatieee) formats.
■
You cannot change the conflict resolution from ignore to a non-ignore
option (time stamp, SPL routine, or time stamp and SPL routine).
You cannot change a non-ignore conflict resolution option to ignore.
However, you can change from time stamp resolution to SPL routine
resolution or from SPL routine resolution to time stamp.
■
The --ats, --ris, --firetrigger, and --fullrow options require a yes (y) or
no (n) argument.
Command-Line Utility Reference A-49
Command Syntax
Special Options
Special Options
Back to cdr modify replicate
p. A-48
-- ats
y
n
-- ris
y
n
-- firetrigger
y
n
-- fullrow
y
n
The following table describes the special options to cdr modify replicate. For
more information on these options, see “Special Options” on page A-13.
Options
Long Form
Short Form
Meaning
--ats y | n
-A y | n
Activate (y) or deactivate (n) aborted-transaction spooling for replicate transactions that
fail to be applied to the target database.
--ris y | n
-R y | n
Activate (y) or deactivate (n) row-information
spooling for replicate row data that fails conflict
resolution or encounters replication-order
problems.
(1 of 2)
A-50 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
Options
Long Form
Short Form
Meaning
--firetrigger y | n
-T y | n
Cause the rows inserted by this replicate to fire
(y) or not fire (n) triggers at the destination.
--fullrow y | n
-f y | n
Specifies to (y) replicate the full row and enable
upserts (default) or (n) replicate only changed
columns and disable upserts.
(2 of 2)
Examples
The following example modifies the frequency attributes of replicate smile to
replicate every five hours:
cdr modify repl -every=300 smile
The following example modifies the frequency attributes of replicate smile to
replicate daily at 1:00 A.M.:
cdr modify repl -a 01:00 smile
The following example modifies the frequency attributes of replicate smile to
replicate on the last day of every month at 5:00 A.M., to generate ATS files, and
not to fire triggers:
cdr modify repl -a L.5:00 -A y -T n smile
The following example changes the mode of the first participant listed to
receive-only and the mode of the second to primary.
cdr mod repl smile “R db1@server1:antonio.table1” \
“P db2@server2:carlo.table2”
See Also
■
“cdr change replicate” on page A-4
■
“cdr define replicate” on page A-10
■
“cdr delete replicate” on page A-24
■
“cdr list replicate” on page A-38
■
“cdr resume replicate” on page A-59
Command-Line Utility Reference A-51
Command Syntax
■
“cdr start replicate” on page A-67
■
“cdr stop replicate” on page A-73
■
“cdr suspend replicate” on page A-77
A-52 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
cdr modify replicateset
The cdr modify replicateset (or cdr modify replset) command modifies all
the replicates in a replicate set.
Syntax
repl _ set
cdr modify replicateset
Connect Option
p. A-87
Frequency Options
p. A-92
Element
repl_set
Purpose
Name of replicate set to modify
Restrictions
The replicate set must exist.
Syntax
“Long Identifiers”
on page A-86
Usage
The cdr modify replicateset command modifies the attributes of all the replicates in the replicate set repl_set. To add or delete replicates from a replicate
set, use the cdr change replicateset command (“cdr change replicateset” on
page A-6).
Important: Once you create a replicateset, you cannot change it from exclusive to
non-exclusive or vice versa.
Command-Line Utility Reference A-53
Command Syntax
Example
The following example connects to the default server ($INFORMIXSERVER)
and modifies the replicate set sales_set to process replication data every
hour:
cdr mod replset --every 60 sales_set
See Also
■
“cdr change replicateset” on page A-6
■
“cdr define replicate” on page A-10
■
“cdr delete replicateset” on page A-26
■
“cdr list replicateset” on page A-42
■
“cdr resume replicateset” on page A-61
■
“cdr start replicateset” on page A-69
■
“cdr stop replicateset” on page A-75
■
“cdr suspend replicateset” on page A-79
A-54 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
cdr modify server
The cdr modify server command modifies the Enterprise Replication
attributes of a database server.
Syntax
server _ group
cdr modify server
Connect Option
p. A-87
-- idle = interval
-- mode
primary
receive-only
-- ats = ats_dir
-- ris = ris_dir
Element
server_group
interval
ats_dir
ris_dir
Purpose
Restrictions
Name of a database server group The database server group must
to modify
be defined in Enterprise
Replication.
Idle time-out for this server
The value must be an integer
>=0.
0 = no timeout.
Name of Aborted Transaction
The directory must be a full
Spooling directory
pathname.
Name of the Row Information
Spooling directory
The directory must be a full
pathname.
Syntax
Integer number of
minutes.
Directory name on
your operating
system.
Directory name on
your operating
system.
Command-Line Utility Reference A-55
Command Syntax
Usage
The cdr modify server command modifies the replication server
server_group.
The following table describes the options to cdr modify server.
Options
Long Form
Short Form
Meaning
--idle
-i
Causes an inactive connection to be terminated after
idle time
--mode
-m
Changes the mode of all replicates using this server
to primary (p) or to receive-only (r)
--ats
-A
Activates aborted-transaction spooling for replicate
transactions that fail to be applied to the target
database
For more information, see Chapter 9, “Monitoring
and Troubleshooting Enterprise Replication.”
--ris
-R
Activates row-information spooling for replicaterow data that fails conflict resolution or encounters
replication-order problems
For more information, see Chapter 9, “Monitoring
and Troubleshooting Enterprise Replication.”
Examples
The following example connects to the database server paris and modifies
the idle time-out of server group g_rome to 10 minutes. ATS files go into the
directory /cdr/atsdir.
cdr modify server -c paris -i 10 -A /cdr/atsdir g_rome
The following example connects to the default database server and sets the
modes of all participants on g_geometrix to primary:
cdr mod ser -m primary g_geometrix
A-56 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
See Also
■
“cdr connect server” on page A-9
■
“cdr define server” on page A-19
■
“cdr delete server” on page A-28
■
“cdr disconnect server” on page A-32
■
“cdr list server” on page A-44
■
“cdr resume server” on page A-63
■
“cdr suspend server” on page A-81
Command-Line Utility Reference A-57
Command Syntax
cdr remove
The cdr remove command removes Enterprise Replication from an HDR
database server.
Syntax
cdr remove
Usage
Use this command to remove Enterprise Replication from an HDR primary
server after it has been started using the oninit -D command. For more information, see “HDR Failure” on page 5-11.
The cdr remove command removes Enterprise Replication from a database
server by deleting its global catalog information. Unlike the cdr delete
command, this command can only be issued when Enterprise Replication is
not active. The database server this command affects is the one specified by
the value of the $INFORMIXSERVER environment variable.
Warning: Do not use this command on a database server that does not participate in
HDR.
A-58 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
cdr resume replicate
The cdr resume replicate command resumes delivery of replication data.
Syntax
repl _ name
cdr resume replicate
Connect Option
p. A-87
Element
repl_name
Purpose
Name of the replicate to change
to active state.
Restrictions
Syntax
The replicate must be suspended. “Long Identifiers”
on page A-86
Usage
The cdr resume replicate command causes all participants in the replicate
repl_name to enter the active state.
For more information on replicate states, refer to “The STATE Column” on
page A-45.
Important: If a replicate belongs to an exclusive replicate set (“Exclusive Replicate
Sets” on page 8-4), you cannot run cdr resume replicate to resume that individual
replicate. You must use cdr resume replicateset to resume all replicates in the
exclusive replicate set.
If a replicate belongs to a non-exclusive replicate set, you can resume the individual
replicates in the set.
Example
The following example connects to the default database server
($INFORMIXSERVER) and resumes the replicate smile:
cdr res repl smile
Command-Line Utility Reference A-59
Command Syntax
See Also
■
“cdr change replicate” on page A-4
■
“cdr define replicate” on page A-10
■
“cdr delete replicate” on page A-24
■
“cdr list replicate” on page A-38
■
“cdr modify replicate” on page A-48
■
“cdr start replicate” on page A-67
■
“cdr stop replicate” on page A-73
■
“cdr suspend replicate” on page A-77
A-60 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
cdr resume replicateset
The cdr resume replicateset (or cdr resume replset) command resumes
delivery of replication data for all the replicates in a replicate set.
Syntax
repl _ set
cdr resume replicateset
Connect Option
p. A-87
Element
repl_set
Purpose
Name of replicate set to resume
Restrictions
None
Syntax
“Long Identifiers”
on page A-86
Usage
The cdr resume replicateset command causes all replicates contained in the
replicate set repl_set to enter the active state for all participants.
Important: If not all the replicates in a non-exclusive replicate set are suspended, the
cdr resume replicateset command displays a warning and only resumes the replicates that are currently suspended.
For more information on replicate states, refer to “The STATE Column” on
page A-45.
Example
The following example connects to the default database server
($INFORMIXSERVER) and resumes the replicate set accounts_set:
cdr res replset accounts_set
Command-Line Utility Reference A-61
Command Syntax
See Also
■
“cdr change replicateset” on page A-6
■
“cdr define replicate” on page A-10
■
“cdr delete replicateset” on page A-26
■
“cdr list replicateset” on page A-42
■
“cdr modify replicateset” on page A-53
■
“cdr start replicateset” on page A-69
■
“cdr stop replicateset” on page A-75
■
“cdr suspend replicateset” on page A-79
A-62 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
cdr resume server
The cdr resume server command resumes delivery of replication data to a
suspended database server.
Syntax
to_server _ group
cdr resume server
Connect Option
p. A-87
Element
to_server_group
from_server_group
Purpose
Name of database server
group to which to resume
delivery of replication data
Name of the database server
group from which to resume
sending data to
to_server_group
from_server _ group
Restrictions
The database server group must
be currently active in Enterprise
Replication.
The database server group must
be currently active in Enterprise
Replication.
Syntax
Usage
The cdr resume server command resumes delivery of replication data to the
to_server_group database server from the database servers included in the
from_server_group list. If the from_server_group list is omitted, the command
resumes replication of data from all database servers participating in the
Enterprise Replication system to the to_server_group. Replication data must
have previously been suspended to the server with the cdr suspend server
command (“cdr suspend server” on page A-81).
Command-Line Utility Reference A-63
Command Syntax
Example
The following example connects to the default server ($INFORMIXSERVER)
and resumes replication of data to the server g_iowa from the servers g_ohio
and g_utah:
cdr sus serv g_iowa g_ohio g_utah
See Also
■
“cdr connect server” on page A-9
■
“cdr define server” on page A-19
■
“cdr delete server” on page A-28
■
“cdr disconnect server” on page A-32
■
“cdr list server” on page A-44
■
“cdr modify server” on page A-55
■
“cdr suspend server” on page A-81
A-64 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
cdr start
The cdr start command starts Enterprise Replication processing.
Syntax
cdr start
Connect Option
p. A-87
Usage
Use cdr start to restart Enterprise Replication after you stop it with cdr stop.
When you issue cdr start, Enterprise Replication brings up all connections to
other adjacent replication servers. Replication servers, replicates, and groups
that were suspended before the cdr stop command was issued remain
suspended; no data is sent for the suspended servers, replicates, or groups.
Enterprise Replication resumes evaluation of the logical log (if required for
the instance of Enterprise Replication) at the replay position. The replay
position is the position where Enterprise Replication stops evaluating the
logical log when cdr stop is executed. If the evaluation process is running
and the logical log ID for the replay position no longer exists when Enterprise
Replication is started, then the restart partially fails (the database server log
contains an error message stating that the replay position is invalid). If the
restart partially fails, no database updates performed on the local database
server are replicated.
Warning: Issue cdr start and cdr stop with extreme caution.
Example
The following example restarts Enterprise Replication processing on
database server utah:
cdr sta -c utah
Command-Line Utility Reference A-65
Command Syntax
See Also
■
“cdr stop” on page A-71
A-66 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
cdr start replicate
The cdr start replicate command starts the capture and transmittal of replication transactions.
Syntax
repl _ name
cdr start replicate
server _ group
Connect Option
p. A-87
Element
repl_name
Purpose
Name of the replicate to start
Restrictions
The replicate must exist.
server_group
Name of database server groups The database server groups must
on which to start the replicate
be defined for Enterprise
Replication.
Syntax
“Long Identifiers”
on page A-86
Usage
The cdr start replicate command causes the replicate repl_name to enter the
active state (capture-send) on the database servers in server_group. If no
server is specified, the repl_name starts on all servers that are included in the
replicate. A replicate can have both active and inactive participants. When at
least one participant is active, the replicate is active.
Important: You cannot start replicates that have no participants.
Important: If a replicate belongs to an exclusive replicate set, you cannot run cdr
start replicate to start that individual replicate. You must use cdr start replicateset to start all replicates in the exclusive replicate set.
Command-Line Utility Reference A-67
Command Syntax
Because Enterprise Replication does not process log records that were
produced before the cdr start replicate command took place, transactions
that occur during this period might be partially replicated. To avoid
problems, either issue the cdr start replicate command on an idle system (no
transactions are occurring) or use the BEGIN WORK WITHOUT REPLICATION
statement until after you successfully start the replicate.
Example
The following command starts the replicate accounts on the server groups
g_svr1 and g_svr2:
cdr sta rep accounts g_svr1 g_svr2
See Also
■
“cdr change replicate” on page A-4
■
“cdr define replicate” on page A-10
■
“cdr delete replicate” on page A-24
■
“cdr list replicate” on page A-38
■
“cdr modify replicate” on page A-48
■
“cdr resume replicate” on page A-59
■
“cdr stop replicate” on page A-73
■
“cdr suspend replicate” on page A-77
A-68 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
cdr start replicateset
The cdr start replicateset (or cdr start replset) command starts the capture
and transmittal of replication transactions for all the replicates in a replicate
set.
Syntax
repl _ set
cdr start replicateset
Connect Option
p. A-87
server _ group
Element
repl_set
Purpose
Name of replicate set to start
Restrictions
The replicate set must exist.
server_group
Names of database server groups The database server groups must
on which to start the replicate set be defined for Enterprise
Replication.
Syntax
“Long Identifiers”
on page A-86
Usage
The replicates defined in the replicate set repl_set enter the active state
(capture-send) on the database servers in server_group.
If the server_group list is omitted, the replicate set repl_set enters the active
state for all database servers participating in the replicate set.
Because Enterprise Replication does not process log records that were
produced before the cdr start replicateset command took place, transactions
that occur during this period might be partially replicated. To avoid
problems, either issue the cdr start replicateset command on an idle system
(no transactions are occurring) or use the BEGIN WORK WITHOUT REPLICATION statement until after you successfully start the replicates in the
replicate set.
Command-Line Utility Reference A-69
Command Syntax
Important: If not all the replicates in a non-exclusive replicate state are inactive, the
cdr start replicateset command displays a warning and only starts the replicates
that are currently inactive.
Example
The following example connects to the default database server specified by
$INFORMIXSERVER and starts the replicate set accounts_set on the server
groups g_hill and g_lake:
cdr sta replset accounts_set g_hill g_lake
See Also
■
“cdr change replicateset” on page A-6
■
“cdr define replicate” on page A-10
■
“cdr delete replicateset” on page A-26
■
“cdr list replicateset” on page A-42
■
“cdr modify replicateset” on page A-53
■
“cdr resume replicateset” on page A-61
■
“cdr stop replicateset” on page A-75
■
“cdr suspend replicateset” on page A-79
A-70 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
cdr stop
The cdr stop command stops Enterprise Replication processing.
Syntax
cdr stop
Connect Option
p. A-87
Usage
In most situations, Enterprise Replication starts when cdr define server is
first executed. The replication threads remain running until the database
server is shut down or until the local database server is deleted with the
cdr delete server command. If you shut down the database server while
Enterprise Replication is running, replication begins again when you restart
the database server.
Under rare conditions, you might want to temporarily stop the Enterprise
Replication processing without stopping the database server. The cdr stop
command shuts down all Enterprise Replication threads in an orderly
manner; however no data to be replicated is captured. When the shutdown
of Enterprise Replication is complete, the message CDR shutdown complete
appears in the database server log file.
After issuing the cdr stop command, replication threads remain stopped
(even if the database server is stopped and restarted) until you issue a cdr
start command.
You cannot delete a server from the enterprise if it is stopped. To delete a
server with cdr delete server, you must issue a cdr start command first.
Warning: If you issue cdr stop and database activity continues, the database server
from which the command is issued and the other database servers participating in
replicates will become inconsistent. To ensure consistency, verify that no database
update activity occurs while Enterprise Replication is stopped.
Command-Line Utility Reference A-71
Command Syntax
Example
The following example stops Enterprise Replication processing on database
server paris. Processing does not resume until a cdr start command restarts
it:
cdr stop -c paris
See Also
■
“cdr start” on page A-65
A-72 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
cdr stop replicate
The cdr stop replicate command stops the capture and transmittal of transactions for replication.
Syntax
repl _ name
cdr stop replicate
Connect Option
p. A-87
Element
repl_name
at_server _ grou
Purpose
Name of the new replicate
Restrictions
Syntax
The replicate must be active and “Long Identifiers”
not in a replicate group.
on page A-86
at_server_group List of database server groups on The database server groups must
which to stop the replicate
be defined for Enterprise
Replication.
Usage
The cdr stop replicate command changes the state of the replicate repl_name
to inactive (no capture, no send) on the replicate servers in the specified
at_server_group list. In addition, this command deletes any data in the send
queue for the stopped replicate.
Important: You cannot stop replicates that have no participants.
Warning: If there was any data in the send queue when you issued the cdr stop
replicate command, or if any database activity occurs while the replicate is stopped,
the replicate servers will get out of sync. For information on resynchronizing replication servers, see “Resynchronizing Replication Servers” on page 6-16.
If you omit the at_server_group list, the replicate enters the inactive state on all
database servers participating in the replicate and all send queues for the
replicate are deleted.
Command-Line Utility Reference A-73
Command Syntax
Important: If a replicate belongs to an exclusive replicate set, you cannot run cdr
stop replicate to stop that individual replicate. You must use cdr stop replicateset
to stop all replicates in the exclusive replicate set.
Example
The following command connects to the database server lake and stops the
replicate aRepl on server groups g_server1 and g_server2:
cdr sto rep -c lake aRepl g_server1 g_server2
See Also
■
“cdr change replicate” on page A-4
■
“cdr define replicate” on page A-10
■
“cdr delete replicate” on page A-24
■
“cdr list replicate” on page A-38
■
“cdr modify replicate” on page A-48
■
“cdr resume replicate” on page A-59
■
“cdr start replicate” on page A-67
■
“cdr suspend replicate” on page A-77
A-74 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
cdr stop replicateset
The cdr stop replicateset (or cdr stop replset) command stops capture and
transmittal transactions for all the replicates in a replicate set.
Syntax
repl _ set
cdr stop replicateset
server _ group
Connect Option
p. A-87
Element
repl_set
Purpose
Name of replicate set to stop
Restrictions
Syntax
“Long Identifiers”
on page A-86
server_group
Name of database server group
on which to stop the replicate
group
The database server groups must
be defined for Enterprise
Replication.
Usage
The cdr stop replicateset command causes all replicates in the replicate set
repl_set to enter the inactive state (no capture, no send) on the database servers
in the server_group list.
If the server_group list is omitted, the replicate set repl_set enters the inactive
state for all database servers participating in the replicate set.
Important: If not all the replicates in the non-exclusive replicate set are active, the
cdr stop replicateset command displays a warning and only stops the replicates
that are currently active.
Command-Line Utility Reference A-75
Command Syntax
Example
The following example connects to the database server paris and stops the
replicate set accounts_set on server groups g_utah and g_iowa:
cdr sto replset --connect=paris accounts_set g_utah g_iowa
See Also
■
“cdr change replicateset” on page A-6
■
“cdr define replicate” on page A-10
■
“cdr delete replicateset” on page A-26
■
“cdr list replicateset” on page A-42
■
“cdr modify replicateset” on page A-53
■
“cdr resume replicateset” on page A-61
■
“cdr start replicateset” on page A-69
■
“cdr suspend replicateset” on page A-79
A-76 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
cdr suspend replicate
The cdr suspend replicate command suspends delivery of replication data.
Syntax
repl _ name
cdr suspend replicate
Connect Option
p. A-87
Element
repl_name
Purpose
Name of the replicate
Restrictions
The replicate must be active.
Syntax
“Long Identifiers”
on page A-86
Usage
The cdr suspend replicate command causes the replicate repl_name to enter
the suspend state (capture, no send) for all participants.
Warning: When a replicate is suspended, Enterprise Replication holds the replication
data in the send queue until the replicate is resumed. If a large amount of data is
generated for the replicate while it is suspended, the send queue space can fill, causing
data to be lost.
Warning: Enterprise Replication does not synchronize transactions if a replicate is
suspended. For example, a transaction that updates tables X and Y will be split if
replication for table X is suspended.
Important: If a replicate belongs to an exclusive replicate set, you cannot run cdr
suspend replicate to stop that individual replicate. You must use cdr suspend
replicateset to suspend all replicates in the exclusive replicate set.
Command-Line Utility Reference A-77
Command Syntax
Example
The following example connects to the database server stan and suspends the
replicate house:
cdr sus repl --connect stan house
See Also
■
“cdr change replicate” on page A-4
■
“cdr define replicate” on page A-10
■
“cdr delete replicate” on page A-24
■
“cdr list replicate” on page A-38
■
“cdr modify replicate” on page A-48
■
“cdr resume replicate” on page A-59
■
“cdr start replicate” on page A-67
■
“cdr stop replicate” on page A-73
A-78 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
cdr suspend replicateset
The cdr suspend replicateset (or cdr suspend replset) command suspends
delivery of replication data for all the replicates in a replicate set.
Syntax
repl _ set
cdr suspend replicateset
Connect Option
p. A-87
Element
repl_set
Purpose
Restrictions
Name of replicate set to suspend
Syntax
“Long Identifiers”
on page A-86
Usage
The cdr suspend replicateset command causes all the replicates in the
replicate set repl_set to enter the suspend state. Information is captured, but
no data is sent for any replicate in the set. The data is queued to be sent when
the set is resumed.
Warning: When a replicate set is suspended, Enterprise Replication holds the replication data in the send queue until the set is resumed. If a large amount of data is
generated for the replicates in the set while it is suspended, the send queue space can
fill, causing data to be lost.
Warning: Enterprise Replication does not synchronize transactions if a replicate in
a replicate set is suspended. For example, a transaction that updates tables X and Y
will be split if replication for table X is suspended.
Important: If not all the replicates in the non-exclusive replicate set are active, the
cdr suspend replicateset command displays a warning and only suspends the replicates that are currently active.
Command-Line Utility Reference A-79
Command Syntax
Example
The following example connects to the default database server specified by
$INFORMIXSERVER and suspends the replicate set accounts_set:
cdr sus replset account_set
See Also
■
“cdr change replicateset” on page A-6
■
“cdr define replicate” on page A-10
■
“cdr delete replicateset” on page A-26
■
“cdr list replicateset” on page A-42
■
“cdr modify replicateset” on page A-53
■
“cdr resume replicateset” on page A-61
■
“cdr start replicateset” on page A-69
■
“cdr stop replicateset” on page A-75
A-80 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
cdr suspend server
The cdr suspend server command suspends the delivery of replication data
to a database server from either a specified list of database servers or from all
database servers in the enterprise.
Syntax
to_server _ group
cdr suspend server
Connect Option
p. A-87
Element
to_server_group
from_server_group
Purpose
Name of database server
group to which to suspend
delivery of replication data
Name of the database server
group from which to stop
sending data to
to_server_group
from_server _ group
Restrictions
The database server group must
be currently active in Enterprise
Replication.
The database server group must
be currently active in Enterprise
Replication.
Syntax
Usage
The cdr suspend server command suspends delivery of replication data to
the to_server_group database server from the database servers included in the
from_server_group list. If the from_server_group list is omitted, the command
suspends replication of data from all database servers participating in the
Enterprise Replication system to the to_server_group.
The connection to the suspended server is unaffected, and control and
acknowledge messages continue to be sent to that server. Enterprise Replication continues to replicate data between all database servers unaffected by
the cdr suspend server command.
Command-Line Utility Reference A-81
Command Syntax
Example
The following example connects to the default server ($INFORMIXSERVER)
and suspends replication of data to the server g_iowa from the servers
g_ohio and g_utah:
cdr sus serv g_iowa g_ohio g_utah
See Also
■
“cdr connect server” on page A-9
■
“cdr define server” on page A-19
■
“cdr delete server” on page A-28
■
“cdr disconnect server” on page A-32
■
“cdr list server” on page A-44
■
“cdr modify server” on page A-55
■
“cdr resume server” on page A-63
A-82 IBM Informix Dynamic Server Enterprise Replication Guide
Command Syntax
Interpreting the Command-Line Utility Syntax
This section defines the terminology and conventions used in the descriptions of the command-line utility (CLU).
Each command follows the same approximate format, with the following
components:
■
Command and its variation
The command specifies the action that should be taken.
■
Options
The options modify the action of the command. Each option starts
with a minus (-) or a double-minus (--).
■
Target
The target specifies the Enterprise Replication object that should be
acted upon.
■
Other objects
Other objects specify objects that are affected by the change to the
target.
If you enter an incorrect cdr command at the command-line prompt, the
database server returns a usage message that summarizes the cdr commands.
For a more detailed usage message, enter cdr variation -h. For example, cdr
list server -h.
Important: You must be the Enterprise Replication server administrator to execute
any of the CLU commands except the cdr list options. For more information, see
“Enterprise Replication Server Administrator” on page 2-4.
This section covers the following topics:
■
Command Abbreviations
■
Option Abbreviations
■
Option Order
■
Long Command-Line Examples
■
Long Identifiers
■
Connect Option
Command-Line Utility Reference A-83
Command Abbreviations
■
Participant
■
Return Codes
■
Frequency Options
Command Abbreviations
For most commands, each of the words that make up a cdr command
variation can be abbreviated to three or more characters. For example, the
following commands are all equivalent:
cdr define replicate
cdr define repl
cdr def rep
The exceptions to this rule are the replicateset commands, which can be
abbreviated to replset. For example, the following commands are equivalent:
cdr define replicateset
cdr def replset
Option Abbreviations
UNIX
Each option for a command has a long form and a short form. You can use
either form, and you can mix long and short forms within a single command.
For example, using long forms on UNIX you can write:
cdr define server --connect=ohio --idle=500 \
--ats=/cdr/ats --initial utah
♦
Windows
On Windows, this command line might look like:
cdr define server --connect=ohio --idle=500 \
--ats=D:\cdr\ats --initial utah
♦
Using short forms, you can write the previous examples as follows:
cdr def ser -c ohio -i 500 -A /cdr/ats -I utah
UNIX
♦
A-84 IBM Informix Dynamic Server Enterprise Replication Guide
Option Order
cdr def ser -c ohio -i 500 -A D:\cdr\ats -I utah
Windows
♦
The long form is always preceded by a double minus (--). Most (but not all)
long forms require an equal sign (=) between the option and its argument.
The short form is preceded by a single minus (-) and is the first letter of the
long form. The short form never requires an equal sign. However, sometimes
the short form is capitalized and sometimes not. To find the correct syntax for
the short form, check the table that accompanies each command variation.
Tip: Use the long forms of options to increase readability.
With the exception of the keyword transaction, all keywords (or letter combinations) that modify the command options must be written as shown in the
syntax diagrams. For example, in the “Conflict Options” on page A-11, the
option (conflict) can be abbreviated, but the keyword ignore cannot be abbreviated. Both of the following forms are correct:
--conflict=ignore
-C ignore
Option Order
You can specify the options of the CLU commands in any order. Some of the
syntax diagrams in this chapter show the options in a specific order because
it makes the diagram easier to read.
Do not repeat any options. The following fragment is incorrect because -c
appears twice. In most cases, the CLU will catch this inconsistency and flag it
as an error. However, if no error is given, the database server uses the last
instance of the option. In the following example, the database server uses the
value -c=utah:
-c=ohio -i=500 -c=utah
Tip: For ease of maintenance, always use the same order for your options.
Command-Line Utility Reference A-85
Long Command-Line Examples
Long Command-Line Examples
The examples in this guide use the convention of a backslash (\) to indicate
that a long command line continues on the next line. The following two
commands are equivalent. The first command is too long to fit on a single
line, so it is continued on the next line. The second example, which uses short
forms for the options, fits on one line.
cdr define server --connect=katmandu --idle=500 \
--ats=/cdrfiles/ats
UNIX
cdr def ser -c=katmandu -i=500 -A=/cdrfiles/ats
♦
Windows
On Windows, these command lines might look like:
cdr define server --connect=honolulu --idle=500 \
--ats=D:\cdrfiles\ats
cdr def ser -c=honolulu -i=500 -A=D:\cdr\ats
♦
For information on how to manage long lines at your command prompt,
check your operating system documentation.
Long Identifiers
Identifiers are the names of objects that Dynamic Server and Enterprise Replication use, such as database servers, databases, columns, replicates, replicate
sets, and so on.
An identifier is a character string that must start with a letter or an underscore. The remaining characters can be letters, numbers, or underscores. On
IBM Informix Dynamic Server, all identifiers, including replicates and
replicate sets, can be 128 bytes long. However, if you have any database
servers in your replication environment that are an earlier version, you must
follow the length restrictions for that version.
For more information about identifiers, see the IBM Informix Guide to SQL:
Syntax.
The location of files, such as the location of the ATS files, can be 256 bytes.
A-86 IBM Informix Dynamic Server Enterprise Replication Guide
Connect Option
User login IDs can be a maximum of 32 bytes. The owner of a table is derived
from a user ID and is thus limited to 32 bytes.
Connect Option
The --connect option causes the command to use the global catalog that is on
the specified server. If you do not specify this option, the connection defaults
to the database server specified by the INFORMIXSERVER environment
variable.
- c server
-- connect = server
- c server_ group
-- connect = server_ group
Element
server
server_group
Purpose
Name of the database server to
connect to
Name of the database server
group that includes the database
server to connect to
Restrictions
The name must be the name of a
database server.
The name must be the name of an
existing database server group.
Syntax
“Long Identifiers”
on page A-86
“Long Identifiers”
on page A-86
You must use the --connect option when you add a database server to your
replication environment with the cdr define server command.
You might use the --connect option if the database server to which you would
normally attach is unavailable.
For more information about the global catalog, refer to “Global Catalog” on
page 2-6.
Command-Line Utility Reference A-87
Participant
Participant
A participant defines the data (database, table, and columns) on a database
server to be replicated. A replicate contains two or more participants. The
participant definition includes the following information:
■
Database server group (“Setting up Database Server Groups” on
page 4-5)
■
Database in which the table resides
■
Table name
■
Table owner (“Table Owner” on page A-89)
■
Participant type (“Participant Type” on page A-89)
■
SELECT statement (“Participant Modifier” on page A-90)
Important: You cannot start and stop replicates that have no participants.
You must include the server group, database, table owner, and table name
when defining a participant, and enclose the entire participant definition in
quote marks.
"
Element
database
owner
server_group
table
database @ server_ group : owner. table
P
O
R
I
Purpose
Restrictions
Name of the database that
The database server must be
includes the table to be replicated registered with Enterprise
Replication.
User ID of the owner of the table
to be replicated
Name of the database server
The database server group name
group that includes the server to must be the name of an existing
connect to
Enterprise Replication server
group in SQLHOSTS.
Name of the table to be replicated The table must be an actual table.
It cannot be a synonym or a view.
A-88 IBM Informix Dynamic Server Enterprise Replication Guide
"
Syntax
“Long Identifiers”
on page A-86
“Long Identifiers”
on page A-86
“Long Identifiers”
on page A-86
“Long Identifiers”
on page A-86
Participant
Important: Do not create more than one replicate definition for each row and column
set of data to replicate. If the participant overlaps, Enterprise Replication attempts to
insert duplicate values during replication.
You can define participants with the following commands:
■
cdr define replicate
■
cdr modify replicate
■
cdr change replicate
Table Owner
The O (owner) option causes permission checks for owner to be applied to the
operation (such as insert or update) that is to be replicated and to all actions
fired by any triggers. When the O option is omitted, all operations are
performed with the privileges of user informix.
UNIX
Windows
If a trigger requires any system-level commands (as specified using the
system( ) command in an SPL statement), the system-level commands are
executed as the table owner, if the participant includes the O option. ♦
If a trigger requires any system-level commands, the system-level commands
are executed as a less privileged user because, on Windows, you cannot
impersonate another user without having the password, whether or not the
participant includes the O option. ♦
Use the I option to disable the table-owner option.
Participant Type
In a primary-target replicate, specify the participant type using the P
(primary) and R (receive-only or target) options in the participant definition.
■
A primary participant both sends and receives replicate data.
■
A target participant only receives data from primary participants.
The replicate can contain multiple primary participants.
In an update-anywhere replicate, do not specify either P or R for the
participant. Enterprise Replication defines the participant as primary in an
update-anywhere replication system.
Command-Line Utility Reference A-89
Participant
For example, in the following definition, replicate Rone is update-anywhere:
cdr define repl-c serv1 -C timestamp -S tran Rone \
"db@serv1:owner.table" "select * from table" \
"db@serv2:owner.table" "select * from table"
In replicate Rtwo, serv2 is the primary and serv1 is receive-only.
cdr define repl-c serv1 -C ignore -S tran Rtwo \
"R db@serv1:owner.table" "select * from table" \
"P db@serv2:owner.table" "select * from table"
For more information, see “Primary-Target Replication System” on page 3-3.
Participant Modifier
The participant modifier is a restricted SELECT statement. The participant
modifier specifies the rows and columns that will be replicated. The
participant modifier must be enclosed in quote marks.
,
"
SELECT
column
FROM
table
WHERE Clause
"
*
Element
column
table
Purpose
Name of a column in the table
specified by the participant
The table specified by the
participant
WHERE Clause Clause that specifies a subset of
table rows to be replicated
Restrictions
The column must exist.
Syntax
“Long Identifiers”
on page A-86
This must be the table name only. “Long Identifiers”
You cannot specify an owner or a on page A-86
database server. You cannot
specify a synonym or a view.
WHERE clause
syntax; refer to
IBM Informix Guide
to SQL: Syntax
A-90 IBM Informix Dynamic Server Enterprise Replication Guide
Participant
Considerations for the SELECT Statement
The following guidelines apply to a SELECT statement that is used as a participant modifier:
■
The statement cannot include a join or a subquery.
■
The FROM clause of the SELECT statement can reference only a single
table.
■
The table in the FROM clause must be the table specified by the
participant.
■
The columns selected must include the primary key.
■
The columns selected can include any columns in the table,
including those that contain smart large objects and TEXT and BYTE
data.
■
The statement cannot perform operations on the selected columns.
■
The statement can include an optional WHERE clause.
The WHERE clause of the SELECT statement of the participant modifier can reference an opaque UDT, as long as the UDT is always stored
in row. For more information, see “Considerations for Replicating
Opaque Data Types” on page 2-26.
For detailed information about the SELECT statement and WHERE clause,
refer to the IBM Informix Guide to SQL: Syntax.
It is recommended that, except for replicating between SERIAL and INT and
between BYTE/TEXT and BLOB/CLOB, you only replicate between like data
types. For example, do not replicate between the following:
■
CHAR(40) to CHAR(20)
■
INT to FLOAT
Command-Line Utility Reference A-91
Return Codes
Return Codes
If the command encounters an error, the database server returns an error
message and a return-code value. The message briefly describes the error. For
information on interpreting the return code, use the cdr finderr command.
Frequency Options
The following commands allow you to specify the interval between replications or the time of day when an action should occur. If you do not specify a
time, the action occurs immediately:
■
cdr define replicate
■
cdr define replicateset
■
cdr modify replicate
■
cdr modify replicateset
Frequency Options
-- immed
-- every = interval
-- at = time
Element
interval
Purpose
Time interval for replication
time
Specific time for replication
Restrictions
Syntax
The smallest interval in minutes. “Intervals” on
page A-94
Time is given with respect to a 24- “Time of Day” on
hour clock.
page A-93
A-92 IBM Informix Dynamic Server Enterprise Replication Guide
Frequency Options
The following table describes the frequency options.
Time Options
Long Form Short Form
Meaning
--immed
-i
Action occurs immediately.
--every
-e
Action occurs immediately and repeats at the
frequency specified by interval.
--at
-a
Action occurs at the specified day and time.
Time of Day
Enterprise Replication always gives the time of day in 24-hour time. For
example, 19:30 is 7:30 P.M. Enterprise Replication always gives times with
respect to the local time, unless the $TZ environment variable is set. However,
Enterprise Replication stores times in the global catalog in Greenwich Mean
Time (GMT).
The -a time option lets you specify the day on which an action should occur.
The string time can have the following formats:
■
Day of week
To specify a specific day of the week, give either the long or short
form of the day, followed by a period and then the time. For example,
--atime Sunday.18:40 or -a Sun.18:40, specifies that the action
should occur every Sunday at 6:40 P.M.
The day of the week is given in the locale of the client. For example,
with a French locale, you might have --atime Lundi.3:30 or
-a Lun.3:30. The time and day are in the time zone of the server.
■
Day of month
To specify a specific date in the month, give the date, followed by a
period, and then the time. For example, 1.3:00 specifies that the
action should occur at 3:00 A.M. on the first day of every month.
The special character L represents the last day of the month. For
example, L.17:00 is 5:00 P.M. on the last day of the month.
Command-Line Utility Reference A-93
Frequency Options
■
Daily
To specify that replication should occur each day, give only the time.
For example, 4:40 specifies that the action should occur every day at
4:40 AM.
Intervals
The -e length option lets you specify the interval between actions. The length
of time between replications can be either of the following formats:
■
The number of minutes
To specify the number of minutes, specify an integer value. For
example, -e 60 indicates 60 minutes between replications.
If you specify the length of time between replications in minutes, the
longest interval allowed is 1966020.
■
The number of hours and minutes
To specify hours and minutes, give the number of hours, followed by
a colon, and then the number of minutes. For example, -e 5:45 indicates 5 hours and 45 minutes between replications.
Important: If you specify the length of time in hours and minutes, the longest
interval allowed is 32767:59.
A-94 IBM Informix Dynamic Server Enterprise Replication Guide
Appendix
Configuration Parameter
and Environment Variable
Reference
The database server configuration file ($ONCONFIG) includes
the following configuration parameters that affect the behavior
of Enterprise Replication:
■
CDR_DBSPACE
■
CDR_DSLOCKWAIT
■
CDR_ENV
■
CDR_EVALTHREADS
■
CDR_MAX_DYNAMIC_LOGS
■
CDR_NIFCOMPRESS
■
CDR_QDATA_SBSPACE
■
CDR_QHDR_DBSPACE
■
CDR_QUEUEMEM
■
CDR_SERIAL
■
ENCRYPT_CDR
■
ENCRYPT_CIPHERS
■
ENCRYPT_MAC
■
ENCRYPT_MACFILE
■
ENCRYPT_SWITCH
Important: If you use both DBSERVERNAME and
DBSERVERALIASES, DBSERVERNAME should refer to the network
connection and not to a shared-memory connection. For information
about database server aliases, refer to the IBM Informix Dynamic Server
Administrator’s Guide.
B
Use the CDR_ENV configuration parameter to set the following environment
variables that affect the behavior of Enterprise Replication:
■
CDR_LOGDELTA
■
CDR_PERFLOG
■
CDR_ROUTER
■
CDR_RMSCALEFACT
B-2 IBM Informix Dynamic Server Enterprise Replication Guide
CDR_DBSPACE Configuration Parameter
units
any valid dbspace
takes effect
when Enterprise Replication is initialized
The CDR_DBSPACE configuration parameter specifies the dbspace where
the syscdr database is created. If it is not set, then syscdr is created in the root
dbspace.
Configuration Parameter and Environment Variable Reference B-3
CDR_DSLOCKWAIT Configuration Parameter
default value
5
units
seconds
takes effect
when shared memory is initialized
The CDR_DSLOCKWAIT configuration parameter specifies the number of
seconds the Datasync (data synchronization) component waits for database
locks to be released. The CDR_DSLOCKWAIT parameter behaves similarly to
the SET LOCK MODE statement. Although the SET LOCK MODE is set by the
end user application, CDR_DSLOCKWAIT is used by Enterprise Replication
while applying data at the target database. This parameter is useful in conditions where different sources require locks on the replicated table. These
sources could be a replicated transaction from another server or a local application operating on that table.
Transactions that receive updates and deletes from another server in the
replicate can abort because of locking problems. If you experience transaction
aborts in the Datasync due to lock timeouts like this, you might want to
increase the value of this parameter.
B-4 IBM Informix Dynamic Server Enterprise Replication Guide
CDR_ENV Configuration Parameter
takes effect
when Enterprise Replication is initialized
The CDR_ENV configuration parameter sets the Enterprise Replication
environment variables CDR_LOGDELTA, CDR_PERFLOG, CDR_ROUTER, or
CDR_RMSCALEFACT. The ONCONFIG file can contain multiple entries for
CDR_ENV. You can specify only one environment variable per CDR_ENV
entry.
For example, to set the CDR_LOGDELTA environment variable to 30 and the
CDR_ROUTER environment variable to 1, include the following lines in the
ONCONFIG file:
CDR_ENV CDR_LOGDELTA=30
CDR_ENV CDR_ROUTER=1
Important: Use the CDR_LOGDELTA, CDR_PERFLOG, CDR_ROUTER, and
CDR_RMSCALEFACT environment variables only if instructed to do so by
Technical Support.
Configuration Parameter and Environment Variable Reference B-5
CDR_EVALTHREADS Configuration Parameter
default value
1,2
units
evaluator thread instances
range of values
1 to 129 * the number of CPU VPs for each value
takes effect
when shared memory is initialized
Enterprise Replication evaluates the images of a row in parallel to assure high
performance. Figure B-1 illustrates how Enterprise Replication uses parallel
processing to evaluate transactions for replication.
Figure B-1
Processing in
Parallel for High
Performance
Evaluating transactions for replication
Thread
Transaction list
Thread
Thread
Fan out
Thread
Logical log
INV#
1234
1235
Product
chandelier
candlestick
INV#
3421
3427
Product
clock
china
INV#
4325
4367
Product
crystal
silverware
INV#
6798
6520
Product
pottery
ceramic_tile
Enterprise
Replication
message queue
The CDR_EVALTHREADS configuration parameter specifies the number of
grouper evaluator threads to create when Enterprise Replication starts and
enables parallelism. The format is:
(per-cpu-vp,additional)
B-6 IBM Informix Dynamic Server Enterprise Replication Guide
The following table provides four examples of CDR_EVALTHREADS.
Number of Threads
Explanation
Example
1,2
1 evaluator thread per CPU VP, plus 2
For a 3 CPU VP server: (3 * 1) + 2 = 5
2
2 evaluator threads per CPU VP
For a 3 CPU VP server: (3 * 2) = 6
2,0
2 evaluator threads per CPU VP
For a 3 CPU VP server: (3* 2)+0 = 6
0,4
4 evaluator threads for any database
server
For a 3 CPU VP server: (3 * 0) +4 = 4
Warning: Do not configure the total number of evaluator threads to be smaller than
the number of CPU VPs in the system.
Configuration Parameter and Environment Variable Reference B-7
CDR_MAX_DYNAMIC_LOGS Configuration
Parameter
default value
0
range of values
■
-1 add dynamic log files indefinitely
■
0 disable dynamic log addition
■
>0 number of dynamic logs that can be added
takes effect
when shared memory is initialized and the DYNAMIC_LOGS
configuration parameter is set to 2. For more information on the
DYNAMIC_LOGS configuration parameter, see the
IBM Informix Dynamic Server Administrator’s Reference.
The CDR_MAX_DYNAMIC_LOGS configuration parameter specifies the
number of dynamic log file requests that Enterprise Replication can make in
one server session.
For more information, see “Preventing DDRBLOCK Mode” on page 9-14.
B-8 IBM Informix Dynamic Server Enterprise Replication Guide
CDR_NIFCOMPRESS Configuration Parameter
default value
0
range of values
■
-1 specifies no compression
■
0 specifies to compress only if the target server expects
compression
■
1 - 9 specifies increasing levels of compression
takes effect
when Enterprise Replication is initialized
The CDR_NIFCOMPRESS (network interface compression) configuration
parameter specifies the level of compression that the database server uses
before sending data from the source database server to the target database
server. Network compression saves network bandwidth over slow links but
uses more CPU to compress and decompress the data.
The values have the following meanings.
Value
Meaning
-1
The source database server never compresses the data, regardless of
whether or not the target site uses compression.
0
The source database server compresses the data only if the target
database server expects compressed data.
1
The database server performs a minimum amount of compression.
9
The database server performs the maximum possible compression.
When Enterprise Replication is defined between two database servers, the
CDR_NIFCOMPRESS values of the two servers are compared and changed to
the higher compression values.
Configuration Parameter and Environment Variable Reference B-9
The compression values determine how much memory can be used to store
information while compressing, as follows:
0
1
2
...6
...8
9
=
=
=
=
=
=
no additional memory
128k + 1k = 129k
128k + 2k = 130k
128k + 32k = 160k
128k + 128k = 256k
128k + 256k = 384k
Higher levels of CDR_NIFCOMPRESS cause greater compression.
Different sites can have different levels. For example, Figure B-2 shows a set
of three root servers connected with LAN and a nonroot server connected
over a modem. The CDR_NIFCOMPRESS configuration parameter is set so
that connections between A, B, and C use no compression. The connection
from C to D uses level 6.
A
D
C
Figure B-2
Database Servers
with Different
Compression
Levels
B
Important: Do not disable NIF compression if the network link performs
compression in hardware.
B-10 IBM Informix Dynamic Server Enterprise Replication Guide
CDR_QDATA_SBSPACE Configuration Parameter
default value
none
separators
comma
range of values
up to 128 characters for each sbspace name; up to 32 sbspace
names. Use a comma to separate each name in the list. At least
one sbspace name must be specified.
takes effect
when Enterprise Replication is initialized
The CDR_QDATA_SBSPACE configuration parameter specifies the list of up to
32 names of sbspaces that Enterprise Replication uses to store spooled transaction row data. Enterprise Replication creates one smart large object per
transaction. If CDR_QDATA_SBSPACE is configured for multiple sbspaces,
then Enterprise Replication uses all appropriate sbspaces in round-robin
order.
Important: You must set the CDR_QDATA_SBSPACE configuration parameter and
create the sbspaces specified by CDR_QDATA_SBSPACE before defining a server for
replication. If the configuration parameter is not set in ONCONFIG or the sbspace
names specified by CDR_QDATA_SBSPACE are invalid, Enterprise Replication fails
to define the server.
For more information, see “Row Data sbspaces” on page 4-14 and “Defining Replication Servers” on page 6-5.
Warning: Do not change the value of CDR_QDATA_SBSPACE while Enterprise
Replication is running.
Configuration Parameter and Environment Variable Reference B-11
CDR_QHDR_DBSPACE Configuration Parameter
default value
the name of the dbspace specified by the ROOTNAME configuration parameter
For more information, see the IBM Informix Administrator’s
Reference.
takes effect
when Enterprise Replication is initialized
The CDR_QHDR_DBSPACE configuration parameter specifies the location of
the dbspace that Enterprise Replication uses to store the transaction record
headers spooled from the send and receive queues. By default, Enterprise
Replication stores the transaction record headers in the root dbspace. For
more information, see “Transaction Record dbspace” on page 4-13.
Warning: Do not change the value of CDR_QHDR_DBSPACE after you initialize
Enterprise Replication.
B-12 IBM Informix Dynamic Server Enterprise Replication Guide
CDR_QUEUEMEM Configuration Parameter
default value
4096
units
kilobytes
range of values
> = 500
takes effect
when shared memory is initialized
The CDR_QUEUEMEM configuration parameter specifies the maximum
amount of memory that is used for the send and receive queues. If your
logical logs are large, the Enterprise Replication reads a large amount of data
into queues in memory. You can use CDR_QUEUEMEM to limit the amount of
memory devoted to the queues.
The maximum memory used for queued elements on a replication server is
the total number of database servers involved in replication, multiplied by
the value of CDR_QUEUEMEM.
When you increase the value of CDR_QUEUEMEM, you reduce the number of
elements that must be written to disk, which can eliminate I/O overhead.
Therefore, if elements are frequently stored on disk, increase the value of
CDR_QUEUEMEM. Conversely, if you set the value of CDR_QUEUEMEM too
high, you might adversely impact the performance of your system. High
values for CDR_QUEUEMEM also increase the time necessary for recovery.
Tune the value of CDR_QUEUEMEM for the amount of memory available on
your computer.
Configuration Parameter and Environment Variable Reference B-13
CDR_SERIAL Configuration Parameter
default value
0,0
units
delta, offset
range of values
0,0 disable control of SERIAL column value generation
>0,>0 enable control of SERIAL column value generation
takes effect
when Enterprise Replication is initialized
The CDR_SERIAL configuration parameter enables control over generating
values for SERIAL and SERIAL8 columns in tables defined for replication. This
is useful for generating unique SERIAL column primary keys in an Enterprise
Replication environment.
The format is:
CDR_SERIAL delta,offset
where:
delta
determines the incremental size of the serial column values
offset
determines the specific number within the delta that will be
generated.
Example CDR_SERIAL Value
Resulting Value for the SERIAL Column
CDR_SERIAL 100,1
1, 101, 201, 301, and so on
CDR_SERIAL 200,2
2, 202, 402, 602, and so on
You should set the delta to greater than the expected number of servers
within your enterprise and make sure the offset is unique on each server.
When you set CDR_SERIAL, only tables that are marked as the source of a
replicate use this method of serial column generation. By default,
CDR_SERIAL is set to 0 to disable control over generating SERIAL and SERIAL8
values.
For more information, see “SERIAL Data Types and Primary Keys” on
page 2-12.
B-14 IBM Informix Dynamic Server Enterprise Replication Guide
ENCRYPT_CDR Configuration Parameter
default value
0
range of values
0 Do not encrypt
1 Encrypt when possible
2 Always encrypt
takes effect
when Enterprise Replication is initialized
The ENCRYPT_CDR configuration parameter sets the level of encryption for
Enterprise Replication.
If the ENCRYPT_CDR configuration parameter is set to 1, then encryption is
used for Enterprise Replication transactions only when the database server
being connected to also supports encryption. This option allows unencrypted
communication with versions of Dynamic Server prior to 9.40.
If the ENCRYPT_CDR configuration parameter is set to 2, then only connections to encrypted database servers are allowed.
If you use both encryption and compression (by setting the
CDR_NIFCOMPRESS configuration parameter), then compression occurs
before encryption.
Configuration Parameter and Environment Variable Reference B-15
ENCRYPT_CIPHER Configuration Parameter
syntax
ENCRYPT_CYPHER all|allbut:<list of ciphers and
modes>|cipher:mode{,cipher:mode ...}
■
all
Specifies to include all available ciphers and modes, except ECB
mode. For example: ENCRYPT_CIPHER all
■
allbut:<list of ciphers and modes>
Specifies to include all ciphers and modes except the ones in the
list. Separate ciphers or modes with a comma. For example:
ENCRYPT_CIPHER allbut:<cbc,bf>
■
cipher:mode
Specifies the ciphers and modes. Separate cipher-mode pairs
with a comma. For example:
ENCRYPT_CIPHER des3:cbc,des3:ofb
default value
allbut:<ecb>
takes effect
when Enterprise Replication is initialized
The ENCRYPT_CIPHER configuration parameter defines all ciphers and
modes that can be used by the current database session.
The cipher list for allbut can include unique, abbreviated entries. For
example, bf can represent bf-1, bf-2, and bf-3. However, if the abbreviation is
the name of an actual cipher, then only that cipher is eliminated. Therefore,
des eliminates only the des cipher, but de eliminates des, des3, and desx.
Important: The encryption cipher and mode used is randomly chosen among the
ciphers common between the two servers. It is strongly recommended that you do not
specify specific ciphers. For security reasons, all ciphers should be allowed. If a
specific cipher is discovered to have a weakness, then that cipher can be eliminated by
using the allbut option.
B-16 IBM Informix Dynamic Server Enterprise Replication Guide
The following ciphers are supported. For an updated list, see the Release
Notes.
des
DES (64-bit key)
bf-1
Blow Fish (64-bit key)
des3 Triple DES
bf-2
Blow Fish (128-bit key)
desx Extended DES (128-bit key)
bf-3
Blow Fish (192-bit key)
The following modes are supported.
ecb
Electronic Code Book (ECB)
cbc
Cipher Block Chaining
ocb
Cipher Feedback
ofb
Output Feedback
All ciphers support all modes, except the desx cipher, which only supports
the cbc mode.
Because cdb mode is considered weak, it is only included if specifically
requested. It is not included in the all or the allbut list.
Configuration Parameter and Environment Variable Reference B-17
ENCRYPT_MAC Configuration Parameter
default value
medium
range of values
One or more of the following options, separated by commas:
■
off does not use MAC generation.
■
low uses XOR folding on all messages.
■
medium uses SHA1 MAC generation for all messages
greater than 20 bytes long and XOR folding on smaller
messages.
■
high uses SHA1 MAC generation on all messages.
For example: ENCRYPT_MAC medium,high
takes effect
when Enterprise Replication is initialized
The ENCRYPT_MAC configuration parameter controls the level of message
authentication code (MAC) generation.
The level is prioritized to the highest value. For example, if one node has a
level of high and medium enabled and the other node has only low enabled,
then the connection attempt fails. Use the off entry between servers only
when a secure network connection is guaranteed.
B-18 IBM Informix Dynamic Server Enterprise Replication Guide
ENCRYPT_MACFILE Configuration Parameter
default value
builtin
units
pathnames, up to 1536 bytes in length
range of values
One or more full path and filenames separated by commas, and
the optional builtin keyword. For example:
ENCRYPT_MACKFILE /usr/local/bin/mac1.dat,
/usr/local/bin/mac2.dat,builtin
takes effect
when Enterprise Replication is initialized
The ENCRYPT_MACFILE configuration parameter specifies a list of the full
path names of MAC key files.
To specify the built-in key, use the keyword builtin. Using the builtin option
provides limited message verification (some validation of the received
message and determination that it appears to have come from a Dynamic
Server client or server). The strongest verification is done by a site-generated
MAC key file.
To generate a MAC key file
1.
Execute the following command from the command line:
GenMacKey –o filename
The filename is the name of the MAC key file.
2.
Update the ENCRYPT_MACFILE configuration parameter on all
Enterprise Replication servers to include the location of the new
MAC key file.
3.
Distribute the new MAC key file.
Each of the entries for the ENCRYPT_MACFILE configuration parameter is
prioritized and negotiated at connect time. The prioritization for the MAC
key files is based on their creation time by the GenMacKey utility. The
builtin option has the lowest priority. Because the MAC key files are
negotiated, you should periodically change the keys.
Configuration Parameter and Environment Variable Reference B-19
ENCRYPT_SWITCH Configuration Parameter
syntax
ENCRYPT_SWITCH cipher_switch_time, key_switch_time
■
cipher_switch_time specifies the minutes between cipher
renegotiation
■
key_switch_time specifies the minutes between secret key
renegotiation
default value
60,60
units
minutes
range of values
positive integers
takes effect
when Enterprise Replication is initialized
The ENCRYPT_SWITCH configuration parameter defines the frequency at
which ciphers or secret keys are renegotiated. The longer the secret key and
encryption cipher remains in use, the more likely the encryption rules might
be broken by an attacker. To avoid this, cryptologists recommend changing
the secret keys on long-term connections. The default time that this renegotiation occurs is once an hour.
B-20 IBM Informix Dynamic Server Enterprise Replication Guide
CDR_LOGDELTA Environment Variable
default value
30
range of values
positive numbers
takes effect
when Enterprise Replication is initialized
The CDR_LOGDELTA environment variable determines when the send and
receive queues are spooled to disk as a percentage of the logical log size. Use
the CDR_ENV configuration parameter to set this environment variable. For
more information, see “CDR_ENV Configuration Parameter” on page B-5.
Important: Do not use the CDR_LOGDELTA environment variable unless instructed
to do so by Technical Support.
Configuration Parameter and Environment Variable Reference B-21
CDR_PERFLOG Environment Variable
default value
0
range of values
positive number
takes effect
when Enterprise Replication is initialized
The CDR_PERFLOG environment variable enables queue tracing, which can
be displayed with the onstat -g que perf command. Use the CDR_ENV configuration parameter to set this environment variable. For more information,
see “CDR_ENV Configuration Parameter” on page B-5.
Important: Do not use the CDR_PERFLOG environment variable unless instructed
to do so by Technical Support.
B-22 IBM Informix Dynamic Server Enterprise Replication Guide
CDR_ROUTER Environment Variable
default value
0
range of values
any number
takes effect
when Enterprise Replication is initialized
When set to 1, the CDR_ROUTER environment variable disables intermediate
acknowledgements of transactions in hierarchical topologies. The normal
behavior for Enterprise Replication is that transaction are acknowledged
when they are received on the first server to which they are sent. When
CDR_ROUTER is set, transactions are only acknowledged when they have
been received on leaf servers. Use the CDR_ENV configuration parameter to
set this environment variable. For more information, see “CDR_ENV Configuration Parameter” on page B-5.
Important: Do not use the CDR_ROUTER environment variable unless instructed
to do so by Technical Support.
Configuration Parameter and Environment Variable Reference B-23
CDR_RMSCALEFACT Environment Variable
default value
4
range of values
positive number
takes effect
when Enterprise Replication is initialized
The CDR_RMSCALEFACT environment variable sets the number of DataSync
threads started for each CPU VP. Specifying a large number of threads can
result in wasted resources. Use the CDR_ENV configuration parameter to set
this environment variable. For more information, see “CDR_ENV Configuration Parameter” on page B-5.
Important: Do not use the CDR_RMSCALEFACT environment variable unless
instructed to do so by Technical Support.
B-24 IBM Informix Dynamic Server Enterprise Replication Guide
Appendix
onstat Command
Reference
This appendix describes forms of the onstat command that are
relevant to Enterprise Replication. The onstat utility reads
shared-memory structures and provides statistics about the
database server that are accurate at the instant that the command
executes. The system-monitoring interface (SMI) also provides
information about the database server. For general information
about onstat and SMI, refer to the Administrator’s Reference. For
information specific to Enterprise Replication, see Appendix D,
“SMI Table Reference.”
C
onstat -g Command Summary
Command
Page
onstat -g ath
C-3
onstat -g cat
C-4
onstat -g ddr
C-5
onstat -g dss
C-5
onstat -g dtc
C-6
onstat -g grp
C-6
onstat -g nif
C-8
onstat -g que
C-8
onstat -g rcv
C-9
onstat -g rep
C-10
onstat -g rqm
C-10
The onstat -g commands are provided for support and debugging only. You
can include only one of these options with each onstat -g command. This
appendix describes the following onstat -g commands:
C-2 IBM Informix Dynamic Server Enterprise Replication Guide
onstat -g ath
onstat -g ath
The onstat -g ath command prints information about all threads.
The following table summarizes the threads that Enterprise Replication uses.
You can use this information about threads when you evaluate memory use.
For more information, see the utilities chapter of the IBM Informix Administrator’s Reference.
Number of
Threads
Thread Name
Thread Description
1
ddr_snoopy
Performs physical I/O from logical log, verifies potential replication, and
sends applicable log-record entries to Enterprise Replication
1
preDDR
Runs during queue recovery to monitor the log and sets blockout mode
if the log position advances too far before replication resumes
1
CDRGfan
Receives log entries and passes entries to evaluator thread
n
CDRGevaln
Evaluates log entry to determine if it should be replicated (n is the
number of evaluator threads specified by CDR_EVALTHREADS)
This thread also performs transaction compression on the receipt of
COMMIT WORK and queues completed replication messages.
1 per large
transaction
CDRPager
Performs the physical IO for the temporary smart large object that holds
paged transaction records
Grouper paging is activated for a transaction when its size is 10 percent
of the value of SHMVIRTSIZE or CDR_QUEUEMEM or when it includes
more than 100,000 records.
1
CDRCparse
Parses all SQL statements for replicate definitions
1 per
connection
CDRNsTn
Sending thread for site
1 per
connection
CDRNrn
Receiving thread for site
2...n
CDRACK_n
Accepts acknowledgments from site
CDRNsAn
At least 2, up to a maximum of the number of active connections
(1 of 2)
onstat Command Reference C-3
onstat -g cat
Number of
Threads
Thread Name
Thread Description
# CPUs...
CDRD_n
Replays transaction on the target system (DataSync thread)
At least one thread is created for each CPU virtual processor (VP). The
maximum number of threads is 4*(number of CPU VPs).
1
CDRSchedMgr
Schedules internal Enterprise Replication events
0 or 1
CDRM_Monitor
Monitors and adjusts DataSync performance for optimum performance
(on the target)
0 or 1
CDRDTCleaner
Deletes (cleans) rows from the deleted rows shadow table when they are
no longer needed
(2 of 2)
onstat -g cat
The onstat -g cat command prints information from the Enterprise Replication global catalog. The global catalog contains a summary of information
about the defined servers, replicates, and replicate sets on each of the servers
within the enterprise. For example, use this command to determine the
current bitmap mask for a given server, which table matches a given
replicate, or whether a server is a root or leaf server.
The onstat -g cat command has the following formats:
onstat -g cat
onstat -g cat scope
onstat -g cat replname
C-4 IBM Informix Dynamic Server Enterprise Replication Guide
onstat -g ddr
The following table describes replname and scope.
Modifier
Description
replname
The name of a replicate
scope
One of the following values:
■
servers
Print information on servers only
■
repls
Print information on replicates only
■
full
Print expanded information for both replicate
servers and replicates
onstat -g ddr
The onstat -g ddr command prints the status of the Enterprise Replication
database log reader. The ddr, or ddr_snoopy, is an internal component of
Enterprise Replication that reads the log buffers and passes information to
the grouper. If log reading is blocked, data might not be replicated until the
problem is resolved. If the block is not resolved, the database server might
overwrite the read (snoopy) position of Enterprise Replication, which means
that data will not be replicated. Once this occurs, you must manually resynchronize the source and target databases. If dynamic log creation is enable
with the CDR_MAX_DYNAMIC_LOGS configuration parameter, this
command prints the number of dynamic log requests made.
onstat -g dss
The onstat -g dss command prints detailed statistical information about the
activity of individual data sync threads. The data sync thread applies the
transaction on the target server. Statistics include the number of applied
transactions and failures and when the last transaction from a source was
applied.
The onstat -g dss command has the following formats:
onstat -g dss
onstat -g dss modifier
onstat Command Reference C-5
onstat -g dtc
The following table describes the values for modifier.
Modifier
Action
UDR
Prints summary information about any UDR invocations by the data
sync threads.
UDRx
Prints expanded information (including a summary of error information) about any UDR invocations by the data sync threads. The
Procid column lists the UDR procedure ID.
onstat -g dtc
The onstat -g dtc command prints statistics about the delete table cleaner. The
delete table cleaner removes rows from the delete table when they are no
longer needed.
The -g dtc option is used primarily as a debugging tool and by Technical
Support.
onstat -g grp
The onstat -g grp command prints statistics about the grouper. The grouper
evaluates the log records, rebuilds the individual log records into the original
transaction, packages the transaction, and queues the transaction for
transmission.
The -g grp option is used primarily as a debugging tool and by Technical
Support.
The onstat -g grp command has the following formats:
onstat -g grp
onstat -g grp modifier
C-6 IBM Informix Dynamic Server Enterprise Replication Guide
onstat -g grp
The following table describes the values for modifier.
Modifier
Action
A
Prints all the information printed by the G, T, P, E, R, and S modifiers
E
Prints grouper evaluator statistics
Ex
Prints grouper evaluator statistics, expands user-defined routine (UDR)
environments
G
Prints grouper general statistics
L
Prints grouper global list
Lx
Prints grouper global list, expands open transactions
M
Prints grouper compression statistics
Mz
Clears grouper compression statistics
P
Prints grouper table partition statistics
pager
Prints grouper paging statistics
R
Prints grouper replicate statistics
S
Prints grouper serial list head
Sl
Prints grouper serial list
Sx
Prints grouper serial list, expands open transactions
T
Prints grouper transaction statistics
UDR
Prints summary information about any UDR invocations by the
grouper threads
UDRx
Prints expanded information (including a summary of error information) about any UDR invocations by the grouper threads
The Procid column lists the UDR procedure ID.
onstat Command Reference C-7
onstat -g nif
onstat -g nif
The onstat -g nif command prints statistics about the network interface,
including a summary of the number of buffers sent and received for each site.
Because this command reports the status of the various network connections
and traffic between the various servers, it can be useful to determine why
data is not replicating.
The -g nif option is used primarily as a debugging tool and by Technical
Support.
The onstat -g nif command has the following formats:
onstat -g nif
onstat -g nif modifier
The following table describes the values for modifier.
Modifier
Action
all
Prints the sum and the sites
sites
Prints the NIF site context blocks
serverid
Prints information about the replication server whose groupID is
serverID
sum
Prints the sum of the number of buffers sent and received for each
site
onstat -g que
The onstat -g que command prints statistics for the high-level queue
interface. The queuer manages the logical aspects of the queue. The RQM
(reliable queue manager) manages the physical queue.
The -g que option is used primarily as a debugging tool and by Technical
Support.
C-8 IBM Informix Dynamic Server Enterprise Replication Guide
onstat -g rcv
onstat -g rcv
The onstat -g rcv command prints statistics about the receive manager. The
receive manager is a set of service routines between the receive queues and
data sync.
The onstat -g rcv command has the following formats:
onstat -g rcv
onstat -g rcv serverid
onstat -g rcv full
The serverID modifier causes the command to print only those output
messages received from the replication server whose groupID is serverid. The
full modifier causes the command to print all statistics.
The onstat -g rcv command includes the Receive Parallelism Statistics
section, a summary of the data sync threads by source server.
Field
Description
Server
Source server ID
Tot.Txn.
Total number of transactions applied from this source server
Pending
Number of current transactions in the pending list for this source
server
Active
Number of current transactions currently being applied from this
source server
MaxPnd
Maximum number of transactions in the pending list queue
MaxAct
Maximum number of transaction in the active list queue
AvgPnd
Average depth of the pending list queue
AvgAct
Average depth of the active list queue
CommitRt
Commit rate of transaction from this source server based on transactions per second
The -g rcv option is used primarily as a debugging tool and by Technical
Support.
onstat Command Reference C-9
onstat -g rep
onstat -g rep
The onstat -g rep command prints events that are in the queue for the
schedule manager. The -g rep option is used primarily as a debugging tool
and by Technical Support.
The onstat -g rep command has the following formats:
onstat -g rep
onstat -g rep replname
The repl_name modifier limits the output to those events originated by the
replicate named repl_name.
onstat -g rqm
The onstat -g rqm command prints statistics and contents of the low-level
queues (send queue, receive queue, ack send queue, sync send queue, and
control send queue) managed by the Reliable Queue Manager (RQM). The
RQM manages the insertion and removal of items to and from the various
queues. The RQM also manages spooling of the in-memory portions of the
queue to and from disk. The -g rqm option displays the contents of the queue,
size of the transactions in the queue, how much of the queue is in memory
and on disk, the location of various handles to the queue, and the contents of
the various progress tables.
If a queue is empty, no information is printed for that queue.
The onstat -g rqm command has the following formats:
onstat -g rqm
onstat -g rqm modifier
The following table describes the values for modifier.
Modifier
Action
ACKQ
Prints the ack send queue
CNTRLQ
Prints the control send queue
RECVQ
Prints the receive queue
(1 of 2)
C-10 IBM Informix Dynamic Server Enterprise Replication Guide
onstat -g rqm
SENDQ
Prints the send queue
SYNCQ
Prints the sync send queue
FULL
Prints full information about every in-memory transaction for every
queue
BRIEF
Prints a brief summary of the number of transactions in each of the
queues and the replication servers for which the data is queued
Use this modifier to quickly identify sites where a problem exists. If
large amounts of data are queued for a single server, then that server
is probably down or off the network.
VERBOSE
Prints all the buffer headers in memory
(2 of 2)
When you specify a modifier to select a specific queue, the command prints
all the statistics for that queue and information about the first and last inmemory transactions for that queue.
The other modifiers of the onstat -g rqm command are used primarily as a
debugging tool and by Technical Support.
onstat Command Reference C-11
onstat -g rqm
C-12 IBM Informix Dynamic Server Enterprise Replication Guide
Appendix
SMI Table Reference
D
The system-monitoring interface (SMI) tables in the sysmaster
database provide information about the state of the database
server. Enterprise Replication uses the SMI tables listed in “SMI
Table Summary” to access information about database servers
declared to Enterprise Replication.
SMI Table Summary
Table
Description
Reference
syscdrack_buf
Buffers for the acknowledge queue
page D-3
syscdrack_txn
Transactions in the acknowledge
queue
page D-3
syscdrctrl_buf
Buffers for the control queue
page D-3
syscdrctrl_txn
Transactions in the control queue
page D-4
syscdrerror
Enterprise Replication error
information
page D-4
syscdrpart
Participant information
page D-5
syscdrprog
Contents of the Enterprise Replication progress tables
page D-5
syscdrq
Queued data information (brief)
page D-6
syscdrqueued
Queued data information (detailed)
page D-7
(1 of 2)
SMI Table Summary
Table
Description
Reference
syscdrrecv_buf
Buffers in the receive queue
page D-7
syscdrrecv_txn
Transactions in the receive queue
page D-7
syscdrrepl
Replicate information
page D-8
syscdrreplset
Replicate set information
page D-9
syscdrs
Server information
page D-10
syscdrsend_buf
Buffers in the send queue
page D-11
syscdrsend_txn
Transactions in the send queue
page D-11
syscdrserver
Database server information
page D-12
syscdrsync_buf
Buffers in the synchronization
queue
page D-13
syscdrsync_txn
Transactions in the synchronization
queue
page D-13
syscdrtx
Transaction information
page D-13
(2 of 2)
D-2 IBM Informix Dynamic Server Enterprise Replication Guide
syscdrack_buf
SMI Tables for Enterprise Replication
The following sections describe the individual tables of the sysmaster
database that refer to Enterprise Replication.
syscdrack_buf
The syscdrack_buf table contains information about the buffers that form the
acknowledgment queue. When the target database server applies transactions, it sends an acknowledgment to the source database server. When the
source database server receives the acknowledgment, it can then delete those
transactions from its send queue.
For information on the columns of the syscdrack_buf table, refer to
“Columns of the Buffer Tables” on page D-17.
syscdrack_txn
The syscdrack_txn table contains information about the acknowledgment
queue. When the target database server applies transactions, it sends an
acknowledgment to the source database server. When the source database
server receives the acknowledgment, it can then delete those transactions
from its send queue.
The acknowledgment queue is an in-memory only queue. That is, it is a
volatile queue that is lost if the database server is stopped.
For information on the columns of the syscdrack_txn table, refer to
“Columns of the Transaction Tables” on page D-16.
syscdrctrl_buf
The syscdrctrl_buf table contains buffers that provide information about the
control queue. The control queue is a stable queue that contains control
messages for the replication system.
For information on the columns of the syscdrctrl_buf table, refer to
“Columns of the Buffer Tables” on page D-17.
SMI Table Reference D-3
syscdrctrl_txn
syscdrctrl_txn
The syscdrctrl_txn table contains information about the control queue. The
control queue is a stable queue that contains control messages for the replication system.
For information on the columns of the syscdrctrl_txn table, refer to “Columns
of the Transaction Tables” on page D-16.
syscdrerror
The syscdrerror table contains information about errors that Enterprise
Replication has encountered.
Column
Type
Description
errornum
integer
Error number
errorserv
char(128)
Database server name where error occurred
errorseqnum
integer
Sequence number that can be used to prune singleerror table
errortime
datetime
year to
second
Time error occurred
sendserv
char(128)
Database server name, if applicable, that initiated
error behavior
reviewed
char(1)
Y if reviewed and set by DBA
N if not reviewed
errorstmnt
text
Error description
D-4 IBM Informix Dynamic Server Enterprise Replication Guide
syscdrpart
syscdrpart
The syscdrspart table contains participant information.
Column
Type
Description
replname
lvarchar
Replicate name
servername
char(128)
Database server name
partstate
char(50)
Participant state: ACTIVE, INACTIVE
partmode
char(1)
P = primary database server (read-write)
R = target database server (receive only)
dbsname
lvarchar
Database name
owner
lvarchar
Owner name
tabname
lvarchar
Table name
syscdrprog
The syscdrprog table lists the contents of the Enterprise Replication progress
tables. The progress tables keep track of what data has been sent to which
servers and which servers have acknowledged receipt of what data. Enterprise Replication uses the transaction keys and stamps to keep track of this
information.
The progress table is two dimensional. For each server to which Enterprise
Replication sends data, the progress tables keep progress information on a
per-replicate basis.
Column
Type
Description
dest_id
integer
Server ID of the destination server
repl_id
integer
The ID that Enterprise Replication uses to identify
the replicate for which this information is valid
source_id
integer
Server ID of the server from which the data
originated
(1 of 2)
SMI Table Reference D-5
syscdrq
Column
Type
Description
key_acked_srv
integer
Last key for this replicate that was acknowledged
by this destination
key_acked_lgid
integer
Logical log ID
key_acked_lgpos
integer
Logical log position
key_acked_seq
integer
Logical log sequence
tx_stamp_1
integer
Together with tx_stamp2, forms the stamp of the
last transaction acknowledged for this replicate
by this destination
tx_stamp_2
integer
Together with tx_stamp1, forms the stamp of the
last transaction acknowledged for this replicate
by this destination
(2 of 2)
syscdrq
The syscdrq table contains information about Enterprise Replication queues.
Column
Type
Description
srvid
integer
The identifier number of the database server
repid
integer
The identifier number of the replicate
srcid
integer
The server ID of the source database server
In cases where a particular server is forwarding data
to another server, srvid is the target and srcid is the
source that originated the transaction.
srvname
char(128)
The name of the database server
replname
char(128)
Replicate name
srcname
char(128)
The name of the source database server
bytesqueued
integer
Number of bytes queued
D-6 IBM Informix Dynamic Server Enterprise Replication Guide
syscdrqueued
syscdrqueued
The syscdrqueued table contains data-queued information.
Column
Type
Description
servername
char(128)
Sending to database server name
name
char(128)
Replicate name
bytesqueued
decimal(32,0)
Number of bytes queued for the server
servername
syscdrrecv_buf
The syscdrrecv_buf table contains buffers that provide information about the
data-receive queue. When a replication server receives replicated data from
a source database server, it puts this data on the receive queue for processing.
On the target side, Enterprise Replication picks up transactions from this
queue and applies them on the target.
For information on the columns of the syscdrrecv_buf table, refer to
“Columns of the Buffer Tables” on page D-17.
syscdrrecv_txn
The syscdrrecv_txn table contains information about the data receive queue.
The receive queue is an in-memory queue.
When a replication server receives replicated data from a source database
server, it puts this data on the receive queue, picks up transactions from this
queue, and applies them on the target.
For information on the columns of the syscdrrecv_txn table, refer to
“Columns of the Transaction Tables” on page D-16.
SMI Table Reference D-7
syscdrrepl
syscdrrepl
The syscdrrepl table contains replicate information.
Column
Type
Description
replname
lvarchar
Replicate name
replstate
char(50)
Replicate state
For possible values, refer to “The STATE Column”
on page A-45.
freqtype
char(1)
Type of replication frequency:
C = continuous
I = interval
T = time based
M = day of month
W = day of week
freqmin
smallint
Minute (after the hour) refresh should occur
Null if continuous
freqhour
smallint
Hour refresh should occur
Null if continuous
freqday
smallint
Day of week or month refresh should occur
scope
char(1)
Replication scope:
T = transaction
R = row-by-row
invokerowspool
char(1)
Y = row spooling is invoked
N = no row spooling is invoked
invoke
transpool
char(1)
Y = transaction spooling is invoked
N = no transaction spooling is invoked
primresolution
char(1)
Type of primary conflict resolution:
I = ignore
T = time stamp
S = SPL routine
secresolution
char(1)
Type of secondary conflict resolution:
S = SPL routine
Null = not configured
(1 of 2)
D-8 IBM Informix Dynamic Server Enterprise Replication Guide
syscdrreplset
Column
Type
storedprocname lvarchar
Description
Name of SPL routine for secondary conflict
resolution
Null if not defined.
floattype
char(1)
C = converts floating point numbers to canonical
format
I= converts floating point numbers to IEEE format
N= does not convert floating point numbers (sends
in native format)
istriggerfire
char(1)
Y = triggers are invoked
N = triggers are not invoked
isfullrow
char(1)
Y = sends the full row and enables upserts
N = sends only changed columns and disables
upserts.
(2 of 2)
syscdrreplset
The syscdrreplset table contains replicate set information.
Column
Type
Description
replname
lvarchar
Replicate name
replsetname
lvarchar
Replicate set name
SMI Table Reference D-9
syscdrs
syscdrs
The syscdrs table contains information about database servers that have been
declared to Enterprise Replication.
Column
Type
Description
servid
integer
Server identifier
servname
char(128)
Database server name
cnnstate
char(1)
Status of connection to this database server:
C = Connected
D = Connection disconnected (will be retried)
T = Idle time-out caused connection to terminate
X = Connection closed by user command
Connection unavailable until reset by user
cnnstatechg
integer
Time that connection state was last changed
servstate
char(1)
Status of database server:
A = Active
S = Suspended
Q = Quiescent (initial sync state only)
ishub
char(1)
Y = Server is a hub
N = Server is not a hub
A hub is any replication server that forwards information to another replication server.
isleaf
char(1)
Y = Server is a leaf server
N = Server is not a leaf server
rootserverid
integer
The identifier of the root server
forwardnodeid
integer
The identifier of the parent server
timeout
integer
Idle timeout
D-10 IBM Informix Dynamic Server Enterprise Replication Guide
syscdrsend_buf
Although not directly connected, a nonroot server is similar to a root server
except it forwards all replicated messages through its parent (root) server. All
nonroot servers are known to all root servers and other nonroot servers. A
nonroot server can be a terminal point in a tree or it can be the parent for
another nonroot server or a leaf server. Nonroot and root servers are aware
of all replication servers in the replication environment, including all the leaf
servers.
A leaf server is a nonroot server that has a partial catalog. A leaf server has
knowledge only of itself and its parent server. It does not contain information
about replicates of which it is not a participant. The leaf server must be a
terminal point in a replication hierarchy.
syscdrsend_buf
The syscdrsend_buf table contains buffers that give information about the
send queue. When a user performs transactions on the source database
server, Enterprise Replication queues the data on the send queue for delivery
to the target servers.
For information on the columns of the syscdrsend_buf table, refer to
“Columns of the Buffer Tables” on page D-17.
syscdrsend_txn
The syscdrsend_txn table contains information about the send queue. When
a user performs transactions on the source database server, Enterprise Replication queues the data on the send queue for delivery to the target servers.
For information on the columns of the syscdrsync_txn table, refer to
“Columns of the Transaction Tables” on page D-16.
SMI Table Reference D-11
syscdrserver
syscdrserver
The syscdrserver table contains information about database servers declared
to Enterprise Replication.
Column
Type
Description
servid
integer
Replication server ID
servername
char(128)
Database server group name
connstate
char(1)
Status of connection to this database server:
C = Connected
D = Connection disconnected (will be retried)
T = Idle time-out caused connection to terminate
X = Connection closed by user command
Connection unavailable until reset by user
connstatechange
integer
Time that connection state was last changed
servstate
char(50)
Status of this database server:
A = Active
S = Suspended
Q = Quiescent (initial sync state only)
ishub
char(1)
Y = Server is a hub
N = Server is not a hub
isleaf
char(1)
Y = Server is a leaf server
N = Server connection is not a leaf server
rootserverid
integer
The identifier of the root server
forwardnodeid
integer
The identifier of the parent server
idletimeout
integer
Idle time-out
atsdir
lvarchar
ATS directory spooling name
risdir
lvarchar
RIS directory spooling name
D-12 IBM Informix Dynamic Server Enterprise Replication Guide
syscdrsync_buf
syscdrsync_buf
The syscdrsync_buf table contains buffers that give information about the
synchronization queue. Enterprise Replication uses this queue only when
defining a replication server and synchronizing its global catalog with
another replication server.
For information on the columns of the syscdrsync_buf table, refer to
“Columns of the Buffer Tables” on page D-17.
syscdrsync_txn
The syscdrsync_txn table contains information about the synchronization
queue. This queue is currently used only when defining a replication server
and synchronizing its global catalog with another replication server. The
synchronization queue is an in-memory-only queue.
For information on the columns of the syscdrsync_txn table, refer to
“Columns of the Transaction Tables” on page D-16.
syscdrtx
The syscdrtx table contains information about Enterprise Replication
transactions.
Column
Type
Description
srvid
integer
Server ID
srvname
char(128)
Name of database server from which data is
received
txprocssd
integer
Transaction processed from database server srvname
txcmmtd
integer
Transaction committed from database server
srvname
txabrtd
integer
Transaction aborted from database server srvname
(1 of 2)
SMI Table Reference D-13
syscdrtx
Column
Type
Description
rowscmmtd
integer
Rows committed from database server srvname
rowsabrtd
integer
Rows aborted from database server srvname
txbadcnt
integer
Number of transactions with source commit time
(on database server srvname) greater than target
commit time
(2 of 2)
D-14 IBM Informix Dynamic Server Enterprise Replication Guide
syscdrtx
Enterprise Replication Queues
One group of sysmaster tables shows information about Enterprise Replication queues. The sysmaster database reports the status of these queues in
the tables that have the suffixes _buf and _txn.
The name of each table that describes an Enterprise Replication queue is
composed of the following three pieces:
■
syscdr, which indicates that the table describes Enterprise
Replication
■
An abbreviation that indicates which queue the table describes
■
A suffix, either _buf or _txn, which specifies whether the table
includes buffers or transactions
Selecting from these tables provides information about the contents of each
queue. For example, the following SELECT statement returns a list of all transactions queued on the send queue:
SELECT * FROM syscdrsend_txn
The following example returns a list of all transactions queued on the inmemory send queue and returns the number of buffers and the size of each
buffer for each transaction on the send queue:
SELECT cbkeyserverid,cbkeyid,cbkeypos,count(*),sum(cbsize)
from syscdrsend_buf
group by cbkeyserverid, cbkeyid, cbkeypos
order by cbkeyserverid, cbkeyid, cbkeypos
All queues are present on all the replication servers, regardless of whether the
replication server is a source or a target for a particular transaction. Some of
the queues are always empty. For instance, the send queue on a target-only
server is always empty.
Each queue is two-dimensional. Every queue has a list of transaction headers.
Each transaction header in turn has a list of buffers that belong to that
transaction.
SMI Table Reference D-15
Columns of the Transaction Tables
Columns of the Transaction Tables
All the tables whose names end with _txn have the same columns and the
same column definitions. The information in the tables represents only transactions in memory and not those spooled to disk.
The ctstamp1 and ctstamp2 columns combine to form the primary key for
these tables.
Column
Type
Description
ctkeyserverid
integer
Server ID of the database server where this data
originated
This server ID is the group ID from the sqlhosts file
or the SQLHOSTS registry key.
ctkeyid
integer
Logical log ID
ctkeypos
integer
Position in the logical log on the source server for
the transaction represented by the buffer
ctkeysequence
integer
Sequence number for the buffer within the
transaction
ctstamp1
integer
Together with ctstamp2, forms an insertion stamp
that specifies the order of the transaction in the
queue
ctstamp2
integer
Together with ctstamp1, forms an insertion stamp
that specifies the order of the transaction in the
queue
ctcommittime
integer
Time when the transaction represented by this
buffer was committed
ctuserid
integer
Login ID of the user who committed this transaction
ctfromid
integer
Server ID of the server that sent this transaction
Used only in hierarchical replication
D-16 IBM Informix Dynamic Server Enterprise Replication Guide
Columns of the Buffer Tables
Columns of the Buffer Tables
The tables whose names end with _buf give information about the buffers
that form the transactions listed in the _txn table. All the _buf tables have the
same columns and the same column definitions.
Column
Type
Description
cbflags
integer
Internal flags for this buffer
cbsize
integer
Size of this buffer in bytes
cbkeyserverid
integer
Server ID of the database server where this data
originated
This server ID is group ID from the sqlhosts file or
the SQLHOSTS registry key.
cbkeyid
integer
Login ID of the user who originated the transaction
represented by this buffer
cbkeypos
integer
Log position on the source server for the transaction
represented by this buffer
cbkeysequence
integer
Sequence number for this buffer within the
transaction
cbreplid
integer
Replicate identifier for the data in this buffer
cbcommittime
integer
Time when the transaction represented by this
buffer was committed
The following columns combine to form the primary key for this table:
cbkeyserverid, cbkeyid, cbkeypos, cbkeysequence.
The columns cbkeyserverid, cbkeyid, and cbkeypos form a foreign key that
points to the transaction in the _txn table that the buffer represents.
SMI Table Reference D-17
Appendix
Replication Examples
This appendix contains simple examples of replication using the
command-line utility (CLU). Appendix A, “Command-Line Utility
Reference” documents the CLU.
Replication Example Environment
To run the replication examples in this chapter, you need three
Informix database servers. Each database server must be in a
database server group.
This example uses the following environment:
■
Three computers (s1, s2, and s3) are hosts for the
database servers usa, italy, and japan, respectively. Each
computer has active network connections to the other
two computers.
■
The database servers usa, italy, and japan are members
of the database server groups g_usa, g_italy, and
g_japan, respectively.
For information about database server groups, see “Setting up Database Server Groups” on page 4-5.
E
Replication Example Environment
UNIX
■
The UNIX sqlhosts file for each database server contains the
following connectivity information.
g_usa
group
-
-
i=1
usa
ontlitcp
s1
techpubs1
g=g_usa
g_italy
group
-
-
i=8
italy
ontlitcp
s2
techpubs2
g=g_italy
g_japan
group
-
-
i=6
japan
ontlitcp
s3
techpub6
g=g_usa
♦
See Appendix F, “SQLHOSTS Registry Key” for information on how
to prepare the SQLHOSTS connectivity information using the information in the UNIX sqlhosts file. ♦
Windows
■
The ONCONFIG file contains the following CDR_QDATA_SBSPACE
entry:
CDR_QDATA_SBSPACE sbspace #CDR queue smart blob space
You must create an sbspace for the row data and set the
CDR_QDATA_SBSPACE parameter to the location of that sbspace. For
more information, see “Setting Up Send and Receive Queue Spool
Areas” on page 4-12 and “CDR_QDATA_SBSPACE Configuration
Parameter” on page B-11.
■
All commands in this example, except for creation of the sample
databases on italy and japan, are issued from the computer s1.
■
The databases for the examples in this chapter are identical
stores_demo databases with logging, as follows:
❑
Create a database named stores on the usa database server:
s1> dbaccessdemo -log stores
❑
Create a database named stores on the italy database server:
s1> rlogin s2
s2> dbaccessdemo -log stores
❑
Create a database named stores on the japan database server:
s1> rlogin s3
s2> dbaccessdemo -log stores
For information on preparing data for replication, see “Data Preparation Example” on page 4-29.
E-2
IBM Informix Dynamic Server Enterprise Replication Guide
Primary-Target Example
Primary-Target Example
This section contains a simple example of primary-target replication. In
primary-target replication, only changes to the primary table are replicated
to the other tables in the replicate. Changes to the secondary tables are not
replicated.
Preparing for a Primary-Target Replication
In this example, define the g_usa and g_italy database server groups as
Enterprise Replication servers and create a replicate, repl1.
To define the database server groups and create the replicate
1.
Create and populate the database that defines the usa database
server as a replication server:
cdr define server --init g_usa
Before replicating data, you must define the database servers as replication servers. A replication server is a database server that has an
extra database that holds replication information.
The --init option specifies that this server is a new replication server.
When you define a replication server, you must use the name of the
database server group (g_usa) rather than the database server name.
2.
Display the replication server that you defined to verify that the
definition succeeded:
cdr list server
The command returns the following information:
SERVER
ID STATE
STATUS
QUEUE
CONNECTION CHANGED
---------------------------------------------------------g_usa
1 Active
Local
0
Replication Examples E-3
Preparing for a Primary-Target Replication
3.
Define the second database server, italy, as a replication server:
cdr define server --connect=italy --init \
--sync=g_usa g_italy
The --connect option allows you to define italy (on the s2 computer)
while working at the s1 (usa) computer. The --sync option instructs
the command to use the already-defined replication server (g_usa) as
a pattern for the new definition. The --sync option also links the two
replication servers into a replication environment.
Tip: In all options except the --connect option, Enterprise Replication uses the
name of the database server group to which a database server belongs, instead of the
name of the database server itself.
4.
Verify that the second definition succeeded:
cdr list server
The command returns the following information:
SERVER
ID
STATE
STATUS
QUEUE
CONNECTION CHANGED
---------------------------------------------------------------------g_italy 8
Active
Connected 0
JUN 14 14:38:44 2000
g_usa
1
Active
Local
0
5.
Define the replicate repl1:
cdr define replicate --conflict=ignore repl1 \
"P stores@g_usa:informix.manufact" \
"select * from manufact" \
"R stores@g_italy:informix.manufact" \
"select * from manufact"
These lines are all one command. The backslashes (\) at the end of
the lines indicate that the command continues on the next line.
This step specifies that conflicts should be ignored and describes two
participants, usa and italy, in the replicate:
E-4
■
The P indicates that in this replicate usa is a primary server. That
is, if any data in the selected columns changes, that changed data
should be sent to the secondary servers.
■
The R indicates that in this replicate italy is a secondary server
(receive-only). The specified table and columns receive information that is sent from the primary server. Changes to those
columns on italy are not replicated.
IBM Informix Dynamic Server Enterprise Replication Guide
Preparing for a Primary-Target Replication
6.
Display the replicate that you defined, so that you can verify that the
definition succeeded:
cdr list replicate
The command returns the following information:
CURRENTLY DEFINED REPLICATES
-----------------------------------------------REPLICATE:
repl1
STATE:
Inactive
CONFLICT:
Ignore
FREQUENCY:
immediate
QUEUE SIZE:
0
PARTICIPANT:
g_usa:informix.manufact
g_italy:informix.manufact
Step 5 defines a replicate but does not make the replicate active. The
output of step 6 shows that the STATE of the replicate is INACTIVE.
7.
Make the replicate active:
cdr start replicate repl1
8.
Display the replicate so that you can verify that the STATE has
changed to ACTIVE:
cdr list replicate
The command returns the following information:
CURRENTLY DEFINED REPLICATES
-----------------------------------------------REPLICATE:
repl1
STATE:
Active
CONFLICT:
Ignore
FREQUENCY:
immediate
QUEUE SIZE:
0
PARTICIPANT:
g_usa:informix.manufact
g_italy:informix.manufact
If any changes are made to the manufact table, the changes will be
replicated to the other participants in the replicate.
Replication Examples E-5
Cause a Replication
Cause a Replication
Now you can modify the manufact table on the usa database server and see
the change reflected in the manufact table on the italy database server.
To cause a replication
1.
Use DB-Access to insert a value into the manufact table on usa:
INSERT INTO stores@usa:manufact \
VALUES ('AWN','Allwyn','8');
2.
Observe the changes on usa and on italy:
SELECT * from stores@usa:manufact
SELECT * from stores@italy:manufact
Do Not Cause a Replication
In repl1, usa is the primary database server and italy is the target. Changes
made to the manufact table on italy do not replicate to usa.
To not cause a replication
1.
Use DB-Access to insert a value into the manufact table on italy:
INSERT INTO stores@italy:manufact \
VALUES ('ZZZ','Zip','9');
2.
Verify that the change occurred on italy but did not replicate to the
manufact table on usa:
SELECT * from stores@usa:manufact
SELECT * from stores@italy:manufact
Update-Anywhere Example
This example builds on the previous example and creates a simple updateanywhere replication. In update-anywhere replication, changes to any table in
the replicate are replicated to all other tables in the replicate. In this example,
any change to the stock table of the stores database on any database server
in the replicate will be replicated to the stock table on the other database
servers.
E-6
IBM Informix Dynamic Server Enterprise Replication Guide
Preparing for an Update-Anywhere Replication
Preparing for an Update-Anywhere Replication
In this example, define the repl2 replicate.
To prepare for update-anywhere replication
1.
Define the replicate, repl2:
cdr define replicate --conflict=ignore repl2 \
"stores@g_usa:informix.stock" "select * from stock" \
"stores@g_italy:informix.stock" "select * from stock"
These lines are all one command. The backslashes (\) at the end of
the lines indicate that the command continues on the next line.
This step specifies that conflicts should be ignored and describes two
participants, usa and italy (including the table and the columns to
replicate) in the replicate.
Because neither P (primary) nor R (receive-only) is specified, the replicate is defined as update-anywhere. If any data in the selected
columns changes, on either participant, that changed data should be
sent to the other participants in the replicate.
2.
Display all the replicates so that you can verify that your definition
of repl2 succeeded:
cdr list replicate
The command returns the following information:
CURRENTLY DEFINED REPLICATES
--------------------------------------------------------REPLICATE:
repl1
STATE:
Active
CONFLICT:
Ignore
FREQUENCY:
immediate
QUEUE SIZE:
0
PARTICIPANT:
g_usa:informix.manufact
g_italy:informix.manufact
REPLICATE:
STATE:
CONFLICT:
FREQUENCY:
QUEUE SIZE:
PARTICIPANT:
repl2
Inactive
Ignore
immediate
0
g_usa:informix.stock
g_italy:informix.manufact
Although this output shows that repl2 exists, it does not show the
participant modifiers (the SELECT statements) for repl2.
Replication Examples E-7
Preparing for an Update-Anywhere Replication
3.
Display the participant modifiers for repl2:
cdr list replicate repl2
This command returns the following information:
REPLICATE
TABLE
SELECT
-----------------------------------------------------------repl2
stores@g_usa:informix.stock
select * from stock
repl2
stores@g_italy:informix.stock
select * from stock
4.
Add the japan database server to the replication system already
defined in the previous example:
cdr define server --connect=japan --init \
--sync=g_usa g_japan
You can use either g_usa or g_italy in the --sync option.
Enterprise Replication maintains identical information on all servers
that participate in the replication system. Therefore, when you add
the japan database server, information about that server is propagated to all previously-defined replication servers (usa and italy).
5.
Display the replication servers so that you can verify that the
definition succeeded:
cdr list server
The command returns the following information:
SERVER
ID
STATE
STATUS
QUEUE
CONNECTION CHANGED
---------------------------------------------------------------------g_italy 8
Active
Connected 0
JUN 14 14:38:44 2000
g_japan 6
Active
Connected 0
JUN 14 14:38:44 2000
g_usa
1
Active
Local
6.
Add the participant and participant modifier to repl2:
cdr change replicate --add repl2 \
"stores@g_japan:informix.stock" "select * from stock"
7.
Display detailed information about repl2 after adding the participant in step 6:
cdr list replicate repl2
E-8
IBM Informix Dynamic Server Enterprise Replication Guide
Preparing for an Update-Anywhere Replication
The command returns the following information:
REPLICATE
TABLE
SELECT
-----------------------------------------------------------repl2
stores@g_usa:informix.stock
select * from stock
repl2
stores@g_italy:informix.stock
select * from stock
repl2
stores@g_japan:informix.stock
select * from stock
8.
Make the replicate active:
cdr start replicate repl2
Changes made to the stock table on usa are reflected in the stock
tables on both italy and japan.
9.
Display a list of replicates so that you can verify that the STATE of
repl2 has changed to ACTIVE
cdr list replicate
The command returns the following information:
CURRENTLY DEFINED REPLICATES
-----------------------------------------------------REPLICATE:
repl1
STATE:
Active
CONFLICT:
Ignore
FREQUENCY:
immediate
QUEUE SIZE:
0
PARTICIPANT:
g_usa:informix.manufact
g_italy:informix.manufact
REPLICATE:
STATE:
CONFLICT:
FREQUENCY:
QUEUE SIZE:
PARTICIPANT:
repl2
Active
Ignore
immediate
0
g_usa:informix.stock
g_italy:informix.manufact
g_japan:informix.manufact
Replication Examples E-9
Cause a Replication
Cause a Replication
Now you can modify the stock table on one database server and see the
change reflected on the other database servers.
To cause a replication
1.
Use DB-Access to insert a line into the stock table on usa:
INSERT INTO stores@usa:stock VALUES (401, “PRC”, “ski boots”,
200.00, “pair”, “pair”);
2.
Observe the change on the italy and japan database servers:
SELECT * from stores@italy:stock;
SELECT * from stores@japan:stock;
To update the stock table on the japan database server
1.
Use DB-Access to change a value in the stock table on japan:
UPDATE stores@japan:stock SET unit_price = 190.00
WHERE stock_num = 401;
2.
Verify that the change has replicated to the stock table on usa and on
italy:
SELECT * from stores@usa:stock WHERE stock_num = 401;
SELECT * from stores@italy:stock WHERE stock_num = 401;
E-10
IBM Informix Dynamic Server Enterprise Replication Guide
Hierarchy Example
Hierarchy Example
The example in this section adds a replication tree to the fully-connected
environment of the usa, italy, and japan replication servers. The nonroot
servers boston and denver are children of usa. (The leaf server miami is a
child of boston.) Figure E-1 shows the replication hierarchy.
Figure E-1
Hierarchical Tree
Example
italy
root
usa
japan
root
root
boston
denver
nonroot
nonroot
miami
leaf
Replication Examples E-11
Preparing for a Hierarchy Example
Preparing for a Hierarchy Example
To try this example, you need to prepare three additional database servers:
boston, denver, and miami. To prepare the database servers, use the
techniques described in “Replication Example Environment” on page E-1.
Defining a Hierarchy
The following example defines a replication hierarchy that includes denver,
boston, and miami and whose root is usa.
To define a hierarchy
1.
Add boston to the replication hierarchy as a nonroot server attached
to the root server usa:
cdr define server --connect boston --nonroot --init \
--sync g_usa g_boston
The backslash (\) indicates that the command continues on the next
line.
2.
Add denver to the replication hierarchy as a nonroot server attached
to the root server usa:
cdr define server -c denver -I -N --ats=/ix/myats \
-S g_usa g_denver
This command uses short forms for the connect, init, and sync
options. (For information about the short forms, refer to “Option
Abbreviations” on page A-84.) The command also specifies a directory for collecting information about failed replication transactions,
/ix/myats.
3.
List the replication servers as seen by the usa replication server:
cdr list server
The root server usa is fully connected to all the other root servers.
Therefore usa knows the connection status of all other root servers
and of its two child servers, denver and boston. The command
returns the following information:
SERVER
ID
STATE
STATUS
QUEUE
CONNECTION CHANGED
----------------------------------------------------------------------
E-12
g_boston 3
Active
Connected 0
Aug 19 14:20:03 2000
g_denver 27
Active
Connected 0
Aug 19 14:20:03 2000
IBM Informix Dynamic Server Enterprise Replication Guide
Defining a Hierarchy
g_italy
8
Active
Connected 0
Aug 19 14:20:03 2000
g_japan
6
Active
Connected 0
Aug 19 14:20:03 2000
g_usa
1
Active
Local
4.
0
List the replication servers as seen by the denver replication server:
cdr list server --connect denver
The nonroot server denver has a complete global catalog of replication information, so it knows all the other servers in its replication
system. However, denver knows the connection status only of itself
and its parent, usa.
The command returns the following information:
SERVER
ID
STATE
STATUS
QUEUE
CONNECTION CHANGED
---------------------------------------------------------------------g_boston 3
Active
g_denver 27
Active
0
g_italy
8
Active
0
g_japan
6
Active
0
g_usa
1
Active
Connected 0
Local
0
Aug 19 14:20:03 2000
5.
Define miami as a leaf server whose parent is boston:
6.
List the replication servers as seen by miami:
cdr define server -c miami -I --leaf -S g_boston g_miami
cdr list server -c miami
As a leaf replication server, miami has a limited catalog of replication
information. It knows only about itself and its parent.
The command returns the following information:
SERVER
ID
STATE
STATUS
QUEUE
CONNECTION CHANGED
---------------------------------------------------------------------g_boston 3
Active
Connected 0
g_miami
Active
Local
4
Aug19 14:35:17 2000
0
Replication Examples E-13
Defining a Hierarchy
7.
List details about the usa replication server:
cdr list server g_usa
The server is a hub; that is, it forwards replication information to and
from other servers. It uses the default values for idle timeout, send
queue, receive queue, and ATS directory.
The command returns the following information:
NAME
ID
ATTRIBUTES
---------------------------------------------------------------------g_usa
E-14
1
timeout=15 hub sendq=rootdbs recvq=rootdbs atsdir=/tmp
IBM Informix Dynamic Server Enterprise Replication Guide
Appendix
Windows
SQLHOSTS Registry Key
When you install the database server, the setup program creates
the following key in the Windows registry:
HKEY_LOCAL_MACHINE\SOFTWARE\INFORMIX\SQLHOSTS
This branch of the HKEY_LOCAL_MACHINE subtree stores the
sqlhosts information. Each key on the SQLHOSTS branch is the
name of a database server. When you click the database server
name, the registry displays the values of the HOST, OPTIONS,
PROTOCOL, and SERVICE fields for that particular database
server.
Each computer that hosts a database server or a client must
include the connectivity information either in the SQLHOSTS
registry key or in a central registry. When the client application
runs on the same computer as the database server, they share a
single SQLHOSTS registry key.
The Location of the SQLHOSTS Registry Key
When you install the database server on Windows, the installation program asks where you want to store the SQLHOSTS
registry key. You can specify one of the following two options:
■
The local computer where you are installing the
database server
■
Another computer in the network that serves as a
central, shared repository of sqlhosts information for
multiple database servers in the network
F
Local SQLHOSTS Registry Key
Local SQLHOSTS Registry Key
If you use the SQLHOSTS registry key on the local computer, for all database
servers, the correct SQLHOSTS registry key must exist on all computers
involved in replication. In addition, the hosts and services files on each
computer must include information about all database servers.
For example, to set up replication between the server instance srv1 on the
computer host1 and the server instance srv2 on host2, you must ensure the
following:
■
Both host1 and host2 include SQLHOSTS registry key entries for srv1
and srv2.
■
The services file on both computers include the details of the services
used by both database server instances.
Shared SQLHOSTS Registry Key
If you use a shared SQLHOSTS registry key you do not need to maintain the
same sqlhosts information on multiple computers. However, the hosts and
services files on each computer must contain information about all computers
that have database servers.
If you specify a shared SQLHOSTS registry key, you must set the environment
variable INFORMIXSQLHOSTS on your local computer to the name of the
Windows computer that stores the registry. The database server first looks for
the SQLHOSTS registry key on the INFORMIXSQLHOSTS computer. If the
database server does not find an SQLHOSTS registry key on the INFORMIXSQLHOSTS computer, or if INFORMIXSQLHOSTS is not set, the database
server looks for an SQLHOSTS registry key on the local computer.
You must comply with Windows network-access conventions and file
permissions to ensure that the local computer has access to the shared
SQLHOSTS registry key. For information about network-access conventions
and file permissions, see your Windows documentation.
F-2
IBM Informix Dynamic Server Enterprise Replication Guide
Preparing the SQLHOSTS Connectivity Information
Preparing the SQLHOSTS Connectivity Information
Preparing the SQLHOSTS connectivity information consists of setting up
registry keys on each computer that hosts a database server that participates
in a replicate.
To prepare the SQLHOSTS connectivity information
1.
Set up the SQLHOSTS registry key on the local computer.
2.
Set up the database server group registry key on the local computer.
See “Setting Up the Database Server Group Registry Key” on
page F-5.
3.
Set up the SQLHOSTS and group registry keys on all computers that
are participants in the replicate.
See “Setting up the Registry Keys on All Computers” on page F-8.
4.
Ensure that the services files on each computer include entries for all
database servers that are participants in the replicate.
See “Verifying the services Files on All Computers” on page F-8.
Setting up the SQLHOSTS Registry with ISA
Important: It is strongly recommended that you use IBM Informix Server Administrator (ISA), rather than regedt32, to set up the SQLHOSTS registry key and
database server group registry key on your Windows system. In addition, ISA allows
you to administer your replication system from a web browser.
See the online help for ISA for details on setting up the SQLHOSTS registry
key and database server group registry key.
Setting up the SQLHOSTS Registry Key with regedt32
It is recommended that you use ISA to set up the SQLHOSTS registry key.
Important: Use extreme caution with regedt32. If you make mistakes when editing
the registry, you can destroy the configuration, not only of your IBM Informix
products, but of your other applications.
SQLHOSTS Registry Key F-3
Setting up the SQLHOSTS Registry Key with regedt32
To set up SQLHOSTS with regedt32
1.
Run the Windows program, regedt32.
2.
In the Registry Editor window, select the window for the
HKEY_LOCAL_MACHINE subtree.
3.
Click the folder icons to select the \SOFTWARE\INFORMIX\
SQLHOSTS branch.
4.
With the SQLHOSTS key selected, choose Edit➞Add Key.
5.
In the Add Key dialog box, type the name of the database server in
the Key Name dialog box.
Leave the Class dialog box blank. Click OK.
6.
Select the new key that you just made (the key with the database
server name).
7.
Choose Edit➞Add Value.
8.
In the Add Value dialog box, type one of the fields of the sqlhosts
information (HOST, OPTIONS, PROTOCOL, SERVICE) in the Value
Name dialog box.
Do not change the Data Type box. Click OK.
9.
10.
F-4
In the String Editor dialog box, type the value for the field that you
selected and click OK.
Repeat steps 8 and 9 for each field of the sqlhosts information.
IBM Informix Dynamic Server Enterprise Replication Guide
Setting Up the Database Server Group Registry Key
Figure F-1 illustrates the location and contents of the SQLHOSTS registry key.
Figure F-1
sqlhosts Information in the Windows Registry
Setting Up the Database Server Group Registry Key
After you create the registry key for the database server, you must make a
registry key for the database server group that includes the database server.
For more information, refer to “Verifying SQLHOSTS” on page 4-5.
Tip: In this manual (and in Figure F-1 on page F-5), each of the names of the
database server groups are the database server names prefixed by g_. The g_ prefix is
not a requirement; it is just the convention that this manual uses.
SQLHOSTS Registry Key F-5
Setting Up the Database Server Group Registry Key
To set up the database server group registry key
1.
With the SQLHOSTS key selected, choose Edit➞Add Key.
2.
In the Add Key dialog box, type the name of the database server
group in the Key Name dialog box.
This value must correspond to the OPTIONS value in the database
server name key.
Leave the Class dialog box blank. Click OK.
3.
Select the new key that you just made (the key with the database
server group name).
4.
Choose Edit➞Add Value.
5.
In the Add Value dialog box, type one of the fields of the sqlhosts
information (HOST, OPTIONS, PROTOCOL, SERVICE) in the Value
Name dialog box.
Do not change the Data Type dialog box. Click OK.
6.
In the String Editor dialog box, type the value for the field that you
selected and click OK.
For a database server group, enter the following values:
HOST
OPTIONS
PROTOCOL
SERVICE
i=unique-integer-value
group
-
Each database server group must have an associated identifier value
(i=) that is unique among all database servers in your environment.
Enter a minus (-) for HOST and SERVICE to indicate that you are not
assigning specific values to those fields.
7.
With the database server group key selected, choose Edit➞Add Key.
8.
In the Add Key dialog box, type the name of the database server in
the Key Name field.
This value must correspond to the database server key, whose
OPTIONS value was set to the database server group key selected in
step 7.
If you are combining Enterprise Replication with HDR, create keys
for primary and secondary HDR servers under the same database
server group.
F-6
IBM Informix Dynamic Server Enterprise Replication Guide
Setting Up the Database Server Group Registry Key
9.
Repeat steps 1 to 8 for each field of the sqlhosts information.
Figure F-2 illustrates the contents of the database server group registry key after you add the values to the keys.
Figure F-2
Database Server Group Information in the Windows Registry
10.
Exit from the Registry Editor.
SQLHOSTS Registry Key F-7
Setting up the Registry Keys on All Computers
Setting up the Registry Keys on All Computers
Now, update the registry keys on all computers that participate in
replication.
To update the registry keys on all computers
1.
Set up the SQLHOSTS registry key on all computers that participate
in replication.
See “Setting up the SQLHOSTS Registry Key with regedt32” on
page F-3.
2.
Set up the database server group registry key on all computers that
participate in replication.
See “Setting Up the Database Server Group Registry Key” on
page F-5.
Verifying the services Files on All Computers
Finally, on each computer that participates in replication, make sure that the
services file (located in the C:\Windows/system32/drivers/etc/ directory)
contains entries for all the database servers.
To verify the services files on all computers
1.
Check the services file on the first host (for example, host1).
The file might look like this
techpubs27
techpubs28
2.
4599/tcp
4600/tcp
# service for online instance denver
# service for online instance boston
Check the services file on the second host (for example, host2).
The file might should look the same as the file on host1:
techpubs27
techpubs28
F-8
4599/tcp
4600/tcp
IBM Informix Dynamic Server Enterprise Replication Guide
# service for online instance denver
# service for online instance boston
Appendix
Notices
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G-2 IBM Informix Dynamic Server Enterprise Replication Guide
Any performance data contained herein was determined in a controlled
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development-level systems and there is no guarantee that these measurements will be the same on generally available systems. Furthermore, some
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G-4 IBM Informix Dynamic Server Enterprise Replication Guide
A
B C
D
E
F
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K
L
M
N O
P
Q
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S
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U
V W
X
Y
Z
@
Index
Index
A
Abbreviations
cdr define replicate set A-84
commands A-84
options A-84
Aborted rows, and ATS files 9-4
Aborted Transaction Spooling. See
ATS.
Activating
ATS A-13, A-22
RIS A-13, A-22
triggers A-14
Active state
definition of 7-8
replicates A-40
server A-45
ADD CRCOLS
defining shadow columns 4-25
--add option
cdr change replicate 6-15, A-4
cdr change replicateset 8-9, A-6
Adding
chunks to storage spaces 9-16
columns to a table 2-16
participants to replicates 6-15,
A-4
replicates to replicate sets 8-9,
A-6
rowids 2-16
Administering Enterprise
Replication
CLU 1-8
ISA 1-8
overview 2-3
Administration
primary-target replication
systems 3-8
update-anywhere replication
systems 3-9
Advantages, replicating
only changed columns 6-12
Alarms, event 9-20
--all option, cdr error A-35
ALTER FRAGMENT
statement 2-16
ALTER TABLE statement
ADD and DROP CRCOLS 4-26
See also IBM Informix Guide to SQL:
Syntax.
Alters, in-place 4-26
ANSI compliance
level Intro-17
Application-specific routines 3-16
Applying data, process 1-18
Arguments, in SPL routine 3-15,
3-16
Asynchronous
data replication 1-4
propagation, considerations 2-9
--at option 6-10, A-93
time formats A-93
ATS
activating A-13, A-22
capacity planning 4-19
filenames, description of 9-5
modifying directory 6-14
specifying directory 6-6, A-21,
A-55
ATS files
BLOB and CLOB information 9-8
BYTE and TEXT data 9-7
A
B
C
D
E
F
G
H
changed column information 9-8
configuring 6-11
description of 9-3
naming conventions 9-5
preparing to use 9-4
smart large objects 9-8
UDT information 9-8
UDTs 9-8
--ats option 6-6, 6-11, 9-4, A-13
cdr define server A-22
cdr modify replicate A-50
cdr modify server A-56
Attributes
replicate, changing 6-15
viewing 7-4
Average large object size. See
AVG_LO_SIZE parameter.
AVG_LO_SIZE parameter 4-15
B
Backing up databases,
considerations 2-9
Batch jobs 2-15
BEGIN WORK WITHOUT
REPLICATION 2-15, 4-22
behavior 4-23
DB-Access 4-24
ESQL/C 4-24
Bitmap information, in logical log
files 6-13
BLOB and CLOB information
in ATS files 9-8
in RIS files 9-12
BLOB data type
spooled row data 4-14
Blobspaces
inconsistent replicated data 2-20
replicating from 2-20
storing simple large objects 2-20
Blobs. See Simple large objects. 2-20
Blocking replication 4-22
Boldface type Intro-9
Buffer tables, columns D-17
Buffers, transaction, spooling to
disk 4-13, 9-12
Business models, primary-target
systems 3-4
2
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M
N
O
P
Q
BYTE data
ATS files 9-7
distributing 2-24
loading with deluxe mode 4-27
RIS files 9-11
SPL conflict resolution 2-22
storing in tblspaces 2-21
C
Canonical format 6-13, A-14
Capacity planning
for delete tables 4-12
primary-target 3-8
spooling directories 4-19
update-anywhere 3-10
Capture mechanisms
log-based data capture 1-5
trigger-based data capture 1-5
trigger-based transaction
capture 1-5
Cascading deletes,
considerations 2-12
cdr change replicate 6-15, A-4
examples A-5
cdr change replicateset 8-9, A-6
examples A-7
cdr change replset. See cdr change
replicateset.
cdr connect server 7-12, A-9
cdr define replicate 6-7, A-10
defining participants 6-8
examples A-14
options A-13
cdr define replicateset 8-4, A-16
abbreviation A-84
examples A-18
cdr define replset. See cdr define
replicateset.
cdr define server 6-5, A-19
examples A-22
options A-21 to A-22
cdr delete replicate 7-10, A-24
examples A-24
cdr delete replicateset 8-8, A-26
examples A-27
cdr delete replset. See cdr delete
replicateset.
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cdr delete server 7-6, A-28
examples A-29 to A-30
cdr disconnect server 7-11, A-32
examples A-32
cdr error A-34
examples A-36
options A-35
cdr finderr A-37, A-92
cdr list replicate 7-7, A-38
examples A-39, A-41
cdr list replicate brief
examples A-39
cdr list replicateset 8-6, A-42
examples A-42
cdr list replset. See cdr list
replicateset.
cdr list server 7-3, A-44
CONNECTION CHANGED
column A-46
description of output A-45
examples A-44, A-46
QUEUE column A-46
STATE column A-45
STATUS column A-45
viewing network connection
status 7-11
cdr modify replicate 6-15, A-48
examples A-51
options A-50
restrictions A-49
cdr modify replicateset 8-10, A-53
examples A-54
cdr modify replset. See cdr modify
replicateset.
cdr modify server 6-14, A-55
examples A-56
options A-56
CDR record type 6-13
See also IBM Informix Dynamic
Server Administrator’s
Reference.
cdr remove A-58
cdr resume replicate 7-10, A-59
examples A-59
cdr resume replicateset 8-8, A-61
cdr resume replset. See cdr resume
replicateset.
cdr resume server 7-6, A-63
cdr start 7-5, A-65
A
B
C
D
E
F
G
H
examples A-65
cdr start replicate 7-8, A-67
examples A-68
cdr start replicateset 8-7, A-69
examples A-70
cdr start replset. See cdr start
replicateset.
cdr stop 7-5, A-71
examples A-72
cdr stop replicate 7-8, A-73
examples A-74
cdr stop replicateset 8-7, A-75
examples A-76
cdr stop replset. See cdr stop
replicateset.
cdr suspend replicate 7-9, A-77
examples A-78
cdr suspend replicateset 8-7, A-79
examples A-80
cdr suspend replset. See cdr
suspend replicateset.
cdr suspend server 7-5, A-81
examples A-64, A-82
cdrerr.h file A-37
cdrserver shadow column 2-11,
2-21
behavior with BEGIN WORK
WITHOUT
REPLICATION 4-23
definition of 4-12
See also Shadow columns.
cdrtime shadow column 2-11, 2-21
behavior with BEGIN WORK
WITHOUT
REPLICATION 4-23
definition of 4-12
See also Shadow columns.
CDR_DBSPACE parameter 4-20,
B-3
CDR_DSLOCKWAIT
parameter B-4
CDR_ENV parameter B-5
CDR_EVALTHREADS
parameter B-6 to B-7
CDR_LOGDELTA environment
variable B-21
CDR_MAX_DYNAMIC_LOGS
parameter 9-15, B-8
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M
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P
Q
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CDR_NIFCOMPRESS
parameter B-9 to B-10
CDR_PERFLOG environment
variable B-22
CDR_QDATA_SBSPACE
parameter 4-14, 4-16, 4-21, B-11
CDR_QHDR_DBSPACE
parameter 4-13, 4-20, B-12
CDR_QUEUEMEM
parameter 4-12, 4-20, B-13
CDR_RMSCALEFACT
environment variable B-24
CDR_ROUTER environment
variable B-23
CDR_SBSPACE parameter 6-5
CDR_SERIAL parameter 4-21, B-14
Central registry, SQLHOSTS F-1
Changed column information
in ATS files 9-8
in RIS files 9-12
Changed columns, replicating 6-11
Changing
database triggers 6-15
participant mode A-48
replicate attributes 6-15
replicate set state A-61
Child database server 3-20
Choosing a replication network
topology 3-18
Chunks, adding to storage
spaces 9-16
Ciphers, encryption B-16
CLOB data type
spooled row data 4-14
Clock synchronization 2-17, 9-18
Clustered indexes, creating or
altering 2-16
CLU. See
Command-line utility.
Commands.
Code samples, conventions
for Intro-13
Codeset conversion files 2-18
Collision
definition of 1-18
example 1-18
Columns D-16
adding 2-16
dropping 2-16
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modifying type 2-16
primary key 6-12
renaming 2-16
replicating changed only 6-11
shadow. See Shadow columns.
virtual 2-26
columns D-17
Command-line conventions
elements of Intro-11
example diagram Intro-13
how to read Intro-13
Command-line utility
administering Enterprise
Replication
--connect option 6-5
description of A-1
syntax, interpreting A-83
terminology A-83
See also Commands.
Commands
abbreviations A-84
cdr change replicate 6-15, A-4
cdr change replicateset 8-9, A-6
cdr change replset. See
Commands
cdr change replicateset
cdr connect server 7-12, A-9
cdr define replicate 6-8, A-10
cdr define replicateset 8-4, A-16
cdr define replset. See cdr define
replicateset.
cdr define server 6-5, A-19
cdr delete replicate 7-10, A-24
cdr delete replicateset 8-8, A-26
cdr delete replset. See cdr delete
replicateset.
cdr delete server 7-6, A-28
cdr disconnect server 7-11, A-32
cdr error A-34
cdr finderr A-37, A-92
cdr list replicate 7-7, A-38
cdr list replicateset 8-6, A-42
cdr list replset. See cdr list
replicateset.
cdr list server 7-3, 7-11, A-44
cdr modify replicate 6-15, A-48
cdr modify replicateset 8-10, A-53
cdr modify replset. See cdr modify
replicateset.
Index 3
A
B
C
D
E
F
G
H
cdr modify server 6-14, A-55
cdr remove A-58
cdr resume replicate 7-10, A-59
cdr resume replicateset 8-8, A-61
cdr resume replset. See cdr resume
replicateset.
cdr resume server 7-6, A-63
cdr start 7-5, A-65
cdr start replicate 7-8, A-67
cdr start replicateset 8-7, A-69
cdr start replset. See cdr start
replicateset.
cdr stop 7-5, A-71
cdr stop replicate 7-8, A-73
cdr stop replicateset 8-7, A-75
cdr stop replset. See cdr stop
replicateset.
cdr suspend replicate 7-9, A-77
cdr suspend replicateset 8-7, A-79
cdr suspend replset. See cdr
suspend replicateset.
cdr suspend server 7-5, A-81
dbaccess 4-9
error return codes A-92
net time 2-18
oninit 6-4
onmode 6-4
onspaces 4-13, 4-15, 9-16
onstat 9-3, 9-16, C-1 to C-11
onstat -g ath C-3
onstat -g cat C-4
onstat -g ddr C-5
onstat -g dss C-5
onstat -g dtc C-6
onstat -g grp C-6
onstat -g nif C-8
onstat -g que C-8
onstat -g rcv C-9
onstat -g rep C-10
onstat -g rqm C-10
ping 4-9
rdate 2-18
starts 6-4
summary of A-2
synchronizing clocks 2-18
Comment icons Intro-10
Communications support module,
not allowed with ER 4-8
4
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M
N
O
P
Q
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Compliance
with industry standards Intro-17
Configuration parameters. See
Parameters.
Configuration problems,
solving 9-17 to 9-19
Configuring
ATS and RIS files 6-11
logical logs files, for Enterprise
Replication 4-11
trusted environment 4-5
CONFLICT field
cdr list replicate output A-40
--conflict option 6-10, A-12
Conflict resolution
and table hierarchies 2-26
BYTE data 2-22
cdrserver 2-21
cdrtime 2-21
considerations for SPL
routine 3-16
CRCOLS, adding and
dropping 2-16
delete tables 3-13, 4-11
description of 3-10
options A-11
preparing tables for 4-25
rules 3-11
behavior 3-17
changing 6-15
ignore 3-12, 6-10
replicating only changed
columns 6-12
shadow columns 3-11
specifying 6-10
SPL routine 3-14, 6-10
time synchronization 3-14
timestamp 3-13, 6-10
valid combinations 3-11
scope
changing 6-15
options A-11
row 3-17, 6-10
specifying 6-10
transaction 3-17, 6-10
shadow columns 2-21
simple large objects 2-21
specifying options A-11
SPL 2-22
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support for UDRs 3-15
TEXT data 2-22
timestamp 2-17, 2-21
transactional integrity 3-17
triggers 2-13
update-anywhere 3-9
Conflicts, and asynchronous
propagation 2-9
--connect option
and database server name 6-5
and replicate sets 8-3
connecting to another replication
server 7-4
description of A-20
Connected status, replication
servers A-45
Connecting status, replication
servers A-45
Connecting to a database
server A-9
CONNECTION CHANGED
column, cdr list server
output A-46
Connections, testing network 4-9
Considerations
distributed transactions 2-14
large transactions 2-15
memory use C-3
planning to use Enterprise
Replication 2-8
primary-target replication
systems 3-8
replicating
changed columns only 6-12
extensible data types 2-26
replication
environment 2-17
volume 2-14
SELECT statement A-91
SPL routines for conflict
resolution 3-16
transaction processing 2-14
Consistency, ensuring 4-22
Consolidation replication. See
Many-to-one replication.
Constraints
checking 3-18
primary key 2-11
referential 6-11
A
B
C
D
E
F
G
H
Contact information Intro-17
Conventions
ATS files 9-5
code samples Intro-13
command-line utility A-83
database server groups 4-6
documentation Intro-9
CRCOLS. See Shadow columns.
CREATE TABLE statement 4-26
See also IBM Informix Guide to SQL:
Syntax.
Creating
clustered indexes 2-16
databases with unbuffered
logging 2-10
demonstration databases Intro-5
replicate sets 8-4
row data sbspace 4-14, 4-15
Cross-replication, between simple
large objects and smart large
objects 2-21
Customizing
replicate sets 8-5
replicates 6-7
replication server definition 6-6
D
Data
applying 1-18
capture types 1-5
distributing 1-18
inconsistent 2-20
loading 4-26
maintaining consistency 1-7
preparing 4-22
unloading 4-26
Data delivery
resuming A-59, A-61, A-63
suspending
for replicate sets A-79
for replicates A-77
for replication servers A-81
Data dissemination model,
description of 3-4
Data propagation, considerations
for asynchronous 2-9
I
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K
L
M
N
O
P
Q
Data replication
asynchronous, definition of 1-4
capture mechanisms
log-based data capture 1-5
trigger-based data capture 1-5
trigger-based transaction
capture 1-5
definition of 1-3
synchronous, definition of 1-4
Data types
built-in 1-8
extensible 2-26
FLOAT 6-13
floating point 2-19
SERIAL 2-12
SERIAL and SERIAL8 2-19
SERIAL8 2-12
SMALLFLOAT 6-13
support for 2-25
supported Intro-6, 2-19
user-defined 1-8
See also UDTs.
Database server groups
conventions 4-6
HDR, defining for 5-9
registry key F-5
SQLHOSTS file 2-5, 4-5
UNIX 4-6
usage 4-6, 6-5
Windows 4-7
See also IBM Informix Dynamic
Server Administrator’s Guide.
Database servers
aliases 4-6, 4-7
connecting to A-9
declaring for Enterprise
Replication 6-3
disconnecting from A-32
initializing 6-4
listing A-44
preparing environment 4-19
preparing for HDR 5-8
removing from Enterprise
Replication A-28
resuming data delivery A-63
specifying type 6-7
suspending data delivery A-81
See also IBM Informix Dynamic
Server Administrator’s Guide.
R
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W
X
Y
Z
@
Database triggers, changing 6-15
Databases
considerations
backing up 2-9
restoring 2-9
creating
demonstration Intro-5
with unbuffered logging 2-10
designing, considerations 2-9
locking 2-15
logging 4-26
unbuffered logging 2-10
DataBlade modules, preparing for
HDR 5-10
Data-consolidation model,
description of 3-5
dbaccess command
testing network environment 4-9
See also
DB-Access utility.
DB-Access User’s Manual.
DB-Access utility
BEGIN WORK WITHOUT
REPLICATION 4-24
included databases Intro-5
dbexport utility 4-28
See also IBM Informix Migration
Guide.
dbimport utility 4-28
See also IBM Informix Migration
Guide.
DBSERVERALIASES
parameter 4-7, 4-20, B-1
DBSERVERNAME parameter 4-7,
4-20, B-1
dbservername, description of 4-7
Dbspaces
creating 4-14
delete table storage 4-11
increasing size 9-17
monitoring disk usage 9-16
pathname limitations 4-13
root 4-13
size of transaction record 4-13
spooled transaction records 4-13
transaction record 4-13
See also
IBM Informix Dynamic Server
Administrator’s Guide.
Index 5
A
B
C
D
E
F
G
H
IBM Informix Dynamic Server
Administrator’s Reference.
DDRBLOCK mode,
preventing 9-14
Deadlock situation, definition
of 3-12
Decision support systems. See DSS.
Declaring database server for
Enterprise Replication 6-3
Default
behavior of Enterprise
Replication 6-11
dbspace for transaction
records 4-13
locale Intro-4
spooling directories 4-19
Defining
participants 6-8
replicate sets A-16
replicates 6-7 to 6-14, A-10
replication servers 6-3, 6-5, A-19
shadow columns 4-25
Definition Failed state A-40
--delete option 6-15, 8-9
cdr change replicate A-4
cdr change replicateset A-6
Delete tables
capacity planning 4-12
definition of 1-19, 4-11
disk space 4-11
in conflict resolution 3-13, 3-15
storage 4-11
timestamp conflict resolution
rule 4-11
Deleted state, server A-45
Deletes, cascading. See Cascading
deletes.
Deleting
Enterprise Replication objects 2-9
participants from replicates 6-15,
A-4
replicate sets 8-8, A-26
replicates from global
catalog 7-10, A-24
replicates from replicate sets 8-9,
A-6
replication servers 7-6, A-28
Deluxe mode without
replication 4-27
6
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J
K
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N
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Demonstration databases Intro-5
Dependencies, software Intro-4
Designing databases and tables 2-9
Determining size
logical log files 4-10
spooled row data sbspace 4-14
transaction record dbspace 4-13
Directories
INFORMIXDIR/bin Intro-5
INFORMIXDIR/gls/cv9 2-18
specifying
ATS location 6-6
RIS location 6-6
spooling, planning for
capacity 4-19
Disconnect status, replication
servers A-45
Disconnecting server
connection A-32
Disk space requirements
delete table 4-11
message queue spooling 4-12
planning 4-10
shadow columns 4-12
Disk usage, monitoring 9-16
Disk, preparing for Enterprise
Replication 4-10
Displaying information about
replicates A-40
Distributed transactions
definition of 2-14
two-phase commit 2-14
Distributing
BYTE and TEXT data 2-24
data, process for 1-18
Distribution replication. See One-tomany replication.
DNS 4-4
Documentation notes Intro-15
Documentation notes, program
item Intro-16
Documentation, types of Intro-14
documentation notes Intro-15
machine notes Intro-15
release notes Intro-15
Domain Name Service. See DNS.
DRINTERVAL parameter 5-13
DROP CRCOLS statement 4-26
DROP TABLE statement 2-16
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Dropped network connections,
reestablishing 7-12
Dropped status, replication
servers A-45
Dropping
columns from a table 2-16
network connection 7-11
rowids 2-16
shadow columns 4-26
DSS, and data consolidation
business model 3-6
Dynamic logs, setting
CDR_MAX_DYNAMIC_LOGS
B-8
E
Enabling triggers 6-14
Encryption
cipher renegotiation B-20
combining with client/server in
SQLHOSTS 4-8
configuration parameters for 4-21
enabling with
ENCRYPT_CDR B-15
HDR, not supported with 5-8
MAC files, specifying B-19
message authentication code
generation B-18
overview 1-8
specifying ciphers and
modes B-16
ENCRYPT_CDR parameter 4-8,
4-21, B-15
ENCRYPT_CIPHER
parameter 4-21, B-16
ENCRYPT_MAC parameter 4-21,
B-18
ENCRYPT_MACFILE
parameter 4-21, B-19
ENCRYPT_SWITCH
parameter 4-21, B-20
English locale 2-18
Enterprise Replication
administering 1-8
administration overview 2-3
and cascading deletes 2-12
and triggers 2-13
A
B
C
D
E
F
G
H
batch jobs 2-15
consistency 1-7
data types 2-19
database server groups for
HDR 5-9
default behavior 6-11
definition of 1-3
deleting and recreating
objects 2-9
encryption, configuring 4-21
evaluation logic 1-10
event alarms 9-20
flexible architecture 1-7
high availability 1-6
managing 2-4
performance 1-6
process for replicating data 1-9
queues D-15
role of logical log files 2-10
selecting replication systems 3-3
server
administrator 2-4
definition of 2-5
definitions in global catalog 2-7
starting A-65
stopping A-71
supported database servers 2-8
synonyms 2-8
terminology 2-5
threads
list of C-3
restarting 7-5
stopping 7-5
using Global Language
Support 2-18
views 2-8
Environment
database server, preparing 4-19
network
preparing 4-3
testing 4-9
trusted, configuring 4-5
Environment variables Intro-9
CDR_LOGDELTA B-21
CDR_PERFLOG B-22
CDR_RMSCALEFACT B-24
CDR_ROUTER B-23
INFORMIXDIR 4-20
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INFORMIXSERVER 4-6, 4-20,
6-5, 7-4
INFORMIXSQLHOSTS 4-20, F-2
setting 4-20
TZ A-93
See also IBM Informix Dynamic
Server Administrator’s
Reference.
en_us.8859-1 locale Intro-4
Error
interpreting error numbers A-37
logging
changing 6-15
setting up 6-11
message files
cdrerr.h A-37
replication server status A-45
return codes A-92
table
managing A-34
ESQL/C, BEGIN WORK
WITHOUT
REPLICATION 4-24
\etc\hosts file 4-4
\etc\hosts.equiv file 4-5
\etc\services file 4-4
/etc/hosts file 4-4
/etc/hosts.equiv file 4-5
/etc/services file 4-4
Evaluating
data
for replication 1-10
data, examples of 1-15
rows 1-10, 1-13
Evaluation logic 1-10
Event alarms 9-20
--every option 6-10, A-93
Examples
adding replicates to replicate
sets 8-9
ATS filenames 9-5
BEGIN WORK WITHOUT
REPLICATION 4-24
BYTE and TEXT data
in ATS files 9-7
in RIS files 9-11 to 9-12
cdr change replicate A-5
cdr change replicateset A-7
cdr define replicate A-14
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cdr define replicateset A-18
cdr define server A-22
cdr delete replicate A-24
cdr delete replicateset A-27
cdr delete server A-29 to A-30
cdr disconnect server A-32
cdr error A-36
cdr list replicate A-39, A-41
cdr list replicate brief A-39
cdr list replicateset A-42
cdr list server A-44, A-46
cdr modify replicate A-51
cdr modify replicateset A-54
cdr modify server A-56
cdr resume replicate A-59
cdr resume replicateset A-61
cdr start A-65
cdr start replicate A-68
cdr start replicateset A-70
cdr stop A-72
cdr stop replicate A-74
cdr stop replicateset A-76
cdr suspend replicate A-78
cdr suspend replicateset A-80
cdr suspend server A-64, A-82
changing frequency for replicate
sets 8-10
collision 1-18
connecting to global catalog 7-4
DB-Access 4-24
defining replicate sets 8-5
deleting
replicate sets 8-8
replicates 7-10
replicates from replicate sets 8-9
replication servers 7-6
evaluating data 1-15
hierarchy E-11
hosts.equiv 4-5
non-exclusive replicate sets 8-5
participant definition 6-9
preparing data for
replication 4-29 to 4-30
primary-target E-3
replicate sets A-76, A-80
replication E-1 to E-14
replication environment E-1
resuming
replicate sets 8-8
Index 7
A
B
C
D
E
F
G
H
replicates 7-10
replication servers 7-6
RIS filenames 9-10
services file 4-5
SQLHOSTS file 4-6
starting
replicate sets 8-7
replicates 7-8
stopping
replicate sets 8-7
replicates 7-8
suspending
replicate sets 8-7
replicates 7-9
replication 7-6
unloading shadow columns 4-27
update-anywhere E-6
updating shadow columns 4-24
using ESQL/C 4-24
Exclusive locks 2-15
--exclusive option 8-4, A-17
Exclusive replicate sets
adding replicates to 8-9
characteristics of 8-4
definition of 8-4
--exclusive option 8-4, A-17
managing replicates 7-7
referential constraints 6-11
resuming replicates 7-10
starting replicates 7-8
stopping replicates 7-9
suspending replicates 7-9
Extended data types
support for 2-25
Extensible data types
support for Intro-6
F
Failed transactions
and RIS files 6-11, 9-9
recorded in ATS files 6-11, 9-3
Fail-safe replication system 3-8
Feature icons Intro-10
Features
extensible data types Intro-6
new Intro-5 to Intro-7
8
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Files
cdrerr.h A-37
hosts 4-4
hosts.equiv 4-5
logical log 4-11
ONCONFIG 2-12, 4-20
services 4-4, 4-5
SQLHOSTS 4-5, 4-6, 4-20
.rhosts 4-5
/etc/hosts 4-4
/etc/hosts.equiv 4-5
/etc/services 4-4
\etc\hosts 4-4
\etc\hosts.equiv 4-5
\etc\services 4-4
finderr utility Intro-16
--firetrigger option 6-14, A-14
modifying replicates A-51
FLOAT data type 6-13
--floatcanon option 6-13, A-14
Floating-point
data types 2-19
numbers
canonical format A-14
IEEE format A-14
numbers, canonical format A-14
values, and canonical message
format 6-13
--follow option, cdr error A-35
Forbidden SQL statements 2-16
Forest of trees
combining with HDR 5-7
definition of 3-22
illustrated 3-22
network topology 1-7
Frequency
attributes
description of 6-10
examples A-51
description of A-92
replication, specifying 6-10
FREQUENCY field, cdr list
replicate output A-41
Full row replication, changing 6-15
--fullrow option 6-11, A-14
modifying replicates A-51
Fully connected topology
definition of 3-19
support for 1-7
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using HDR with 3-19
Functions, writing for UDT
replication 2-25
G
Global catalog
contents of 2-7
description of 2-6
leaf servers 2-7, 4-8
root and nonroot servers 4-8
synchronizing 6-6
Global Language Support
description of Intro-4
locale of date A-93
support of 1-8
using with Enterprise
Replication 2-18
GLS. See Global Language Support.
Grouper paging file, setting
up 4-18
Groups. See Database server
groups.
Guidelines for configuring logical
log files 4-11
H
Hardware platforms
dissimilar 6-13
heterogeneous 2-19
Help Intro-14
Heterogeneous hardware,
replicating on 2-19
Hierarchical routing topologies
combing with HDR 5-6
SQLHOSTS 4-8
supported types 3-19
synchronization server 3-21, 6-6
terminology 3-20
Hierarchical tree
definition of 3-21
network topology 1-7
using HDR with 3-22
Hierarchies
replicating table hierarchies 2-26
replication examples E-11
A
B
C
D
E
F
G
H
High availability
planning
primary-target 3-8
using Enterprise Replication
for 1-6
High-Availability Data Replication
(HDR)
database server groups 4-6
database server groups,
defining 5-9
DRINTERVAL setting 5-13
encryption not supported 5-8
forest of trees topology 5-7
hierarchical routing
topologies 5-6
loading data 5-10
logging sbspaces for spooled row
data 4-16
managing 5-11 to 5-13
oninit -D command 5-12
onmode -d standard
command 5-11
performance 5-13
preparing servers 5-8
primary server failure 5-11
primary-target replication
systems 5-4
replication system 5-3
secondary server, switching
to 5-11
spooled row data sbspace
logging 5-11
starting primary without ER or
HDR 5-12
UDRs, preparing for 5-10
UDTs, preparing for 5-10
update-anywhere replication 5-5
with fully connected
topology 3-19
with hierarchical tree
topology 3-22
High-availability replication
system 5-3
High-Performance Loader 4-27
See also IBM Informix HighPerformance Loader User’s
Guide.
HKEY_LOCAL_MACHINE F-1
hostname, in sqlhosts 4-7
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O
P
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Hosts file, preparing 4-4
hosts.equiv file 4-5
HPL. See High-Performance
Loader.
I
IBM Informix Server Administrator
(ISA) 1-8
setting up SQLHOSTS
registry 4-8, F-3
Icons
feature Intro-10
Important Intro-10
platform Intro-10
product Intro-10
Tip Intro-10
Warning Intro-10
ID column, cdr list server
output A-45
Identifiers A-86
See also IBM Informix Guide to SQL:
Syntax.
--idle option
cdr define server 6-6, A-22
cdr modify server A-56
Idle timeout
modifying 6-14
setting 6-6
specifying A-21
IEEE floating point format 6-13,
A-14
Ignore conflict-resolution rule 3-11,
3-12, 6-10, A-40
database action 3-12
--immed option 6-10, A-93
Immediate frequency A-41
Important paragraphs, icon
for Intro-10
Inactive state
definition of 7-8
description of A-40
Inconsistent data with blobspaces
or sbspaces 2-20
Increasing storage space size 9-17
Indexes, creating or altering
clustered 2-16
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Industry standards, compliance
with Intro-17
Information consistency, updateanywhere 3-9
informix user 2-4
Informix-Admin group,
Windows 2-4
INFORMIXDIR environment
variable 4-20
$INFORMIXDIR/bin
directory Intro-5
$INFORMIXDIR/gls/cv9
directory 2-18
$INFORMIXDIR/incl/esql/
cdrerr.h file A-37
INFORMIXSERVER environment
variable 4-6, 4-20, 6-5, 7-4
INFORMIXSQLHOSTS
environment variable 4-20, F-2
--init option 6-5, A-20
Initializing
database servers 6-4
See also IBM Informix Dynamic
Server Administrator’s Guide.
In-place alters, ADD and DROP
CRCOLS 4-26
Installing
UDTs 2-25
Interval formats A-94
Invalid sbspace 6-5
IP addresses, specifying in hosts
file 4-4
ISA. See IBM Informix Server
Administrator.
ISO 8859-1 code set Intro-4
K
Keys, primary
and constraints 2-11
and SERIAL data types 2-12
and UDT columns 2-26
removing constraints 2-16
L
Large objects, replicating only
changed columns 6-12
Index 9
A
B
C
D
E
F
G
H
Large transactions
grouper paging file 4-18
Large transactions, considerations
for Enterprise Replication 2-15
--leaf option 6-7, A-20
Leaf servers
definition of 3-20
global catalog 2-6, 4-8
limited catalog 2-7
specifying 6-7
SQLHOSTS information 4-8
Limitations, SPL conflict
resolution 3-15
Limited SQL statements 2-16
Listing
Enterprise Replication
servers A-44
replicate sets A-42
replicates A-38
LOAD statement 4-26, 4-28
See also IBM Informix Guide to SQL:
Syntax.
Loading data
ER servers 4-26
HDR servers 5-10
Local status, replication
servers A-45
Locales
different 2-18
Enterprise Replication 2-18
specifying nondefault 2-18
Locking databases 2-15
Locks, exclusive. See Exclusive
locks.
Log-based data capture 1-5
Logging
aborted transactions 9-4
databases, preparing 4-26
errors 6-11
unbuffered 2-10, 4-26
Logging mode, for spooled row
data sbspaces 4-16
LOGGING parameter 4-15
Logical log files 4-11
and maximum transaction
size 4-11
bitmap information about
updated columns 6-13
capacity planning 4-10
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configuration guidelines 4-11
determining size 4-10
disk space
error 9-18
requirements 4-10
dynamically adding 9-15
increasing size 9-13
overwriting 9-14
reading of 1-10
role in Enterprise
Replication 2-10
size 4-11
switching 4-10
See also
IBM Informix Dynamic Server
Administrator’s Guide.
IBM Informix Dynamic Server
Administrator’s Reference.
Logical Log Record reduction
option, and Enterprise
Replication 4-10
Long identifiers A-86
LRD label, RIS files 9-11
LRH label, RIS files 9-11
LRS label, RIS files 9-11
LTXEHWM parameter 4-11
LTXHWM parameter 4-11
M
Machine notes Intro-15
Machine-independent format 6-13,
A-14
Maintaining consistency 1-7
Managing
database servers. See IBM Informix
Dynamic Server Administrator’s
Guide.
Enterprise Replication,
overview 2-4
replicate sets 8-6 to 8-8
replicates 7-7 to 7-10
in exclusive replicate sets 7-7
replication server network
connections 7-11 to 7-12
replication servers 7-3 to 7-7
Many-to-one replication, definition
of 3-4
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Maximum transaction size, and
logical log files 4-11
Memory queues
preventing overflows 9-12
Memory use considerations C-3
Message authentication code B-18
Message authentication code
files B-19
Message file for error
messages Intro-16
Message formats
canonical 6-13
IEEE 6-13
Message queues
CDR_QUEUEMEM
parameter 4-12
definition of 4-12
planning disk space 4-12
--mode option, cdr modify
server A-56
Modes, changing participant A-48
Modes, encryption B-16
Modifying
column types 2-16
primary-key constraint 2-16
replicate attributes A-48
replicate sets 8-9 to 8-10, A-53
replicates 6-15
replication servers 6-14 to 6-16,
A-55
Monitoring
dbspaces, onstat command 9-16
disk usage 9-16
sbspaces 9-16
oncheck command 9-16
onstat command 9-16
See also
IBM Informix Dynamic Server
Administrator’s Guide.
IBM Informix Administrator’s
Reference.
IBM Informix Dynamic Server
Performance Guide.
Multiple
references to a smart large
object 2-24
updates to the same row 1-13
A
B
C
D
E
F
G
H
N
net time command, synchronizing
clocks 2-18
nettype, description of 4-7
Network connections
dropping 7-11
encryption, setting up for 4-8
managing 7-11 to 7-12
reestablishing 7-12
troubleshooting 9-13
viewing status 7-11
Network encryption
See Encryption.
Network environment
preparing 4-3
testing 4-9
See also IBM Informix
Administrator’s Guide.
Network topologies
choosing 3-18
forest of trees 1-7
fully connected 1-7
hierarchical tree 1-7
supported types 3-18
New features Intro-5 to Intro-7
--nomark option, cdr error A-35
Non-exclusive replicate sets
adding replicates to 8-9
characteristics of 8-5
definition of 8-5
example of 8-5
Nonoptimized SPL routine 3-17
--nonroot option 6-7, A-20
Nonroot servers
definition of 3-20
global catalog 2-6, 4-8
specifying type 6-7
SQLHOSTS information 4-8
O
OLTP, and data dissemination
business model 3-4
oncheck command, monitoring
sbspaces 9-16
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ONCONFIG file
configuration
parameters B-1 to B-20
configuring encryption 4-21
setting
DBSERVERALIASES 4-7
DBSERVERNAME 4-7
parameters 2-12, 4-20
ONCONFIG parameters. See
Parameters.
One-to-many replication, definition
of 3-4
oninit command. initializing
database servers 6-4
oninit -D command 5-12
Online help Intro-14
Online manuals Intro-14
Online transaction processing. See
OLTP.
onload utility 4-28
See also IBM Informix Migration
Guide.
onmode command 6-4
onmode -d standard
command 5-11
onspaces command
adding chunks 9-16
creating
row data sbspace 4-15
transaction record dbspace 4-13
onstat command 9-3, C-1 to C-11
monitoring
dbspaces 9-16
sbspaces 9-16
onstat -g ath command C-3
onstat -g cat command C-4
onstat -g ddr command C-5
onstat -g dss command C-5
onstat -g dtc command C-6
onstat -g grp command C-6
onstat -g nif command C-8
onstat -g que command C-8
onstat -g rcv command C-9
onstat -g rep command C-10
onstat -g rqm command C-10
onunload utility 4-26, 4-28
See also IBM Informix Migration
Guide.
S
T
U
V
W
X
Y
Z
@
Operating system times,
synchronizing 2-17, 9-18
Optical devices, not supported 2-19
--optimize option 6-10, A-12
Optimized SPL routine, definition
of 3-17
Options
abbreviations A-84
--add 6-15, 8-9, A-4, A-6
--all A-35
--at 6-10, A-93
--ats 6-6, 6-11, 9-4, A-13, A-22,
A-50, A-56
cdr define replicate A-13
cdr define server A-21 to A-22
cdr error A-35
cdr modify replicate A-50
cdr modify server A-56
--conflict 6-10, A-12
conflict resolution A-11
--connect 6-5, 7-4, 8-3, A-20
--connect option A-87
--delete 6-15, 8-9, A-4, A-6
--every 6-10, A-93
--exclusive 8-4, A-17
--firetrigger 6-14, A-14, A-51
--floatcanon 6-13, A-14
--follow A-35
frequency A-92
--fullrow 6-11, A-14, A-51
--idle 6-6, A-22, A-56
--immed 6-10, A-93
in SQLHOSTS, description of 4-7
--init 6-5, A-20
--leaf 6-7, A-20
--mode A-56
--nomark A-35
--nonroot 6-7, A-20
--optimize 6-10, A-12
order of A-85
participant owner A-89
primary A-89
--prune A-35
read-only A-89
--ris 6-6, 6-11, 9-9, A-13, A-22,
A-50, A-56
scope A-11
--scope 6-10, A-12
--seq A-35
Index 11
A
B
C
D
E
F
G
H
--sync 6-6, A-20
--zap A-35
Out-of-row data, sharing during
replication 2-24
Overflowing memory queues,
preventing 9-12
Overview of Enterprise Replication
administration 2-3
Overwriting logical log files 9-14
P
Parameters
AVG_LO_SIZE 4-15
CDR_DBSPACE 4-20, B-3
CDR_DSLOCKWAIT B-4
CDR_ENV B-5
CDR_EVALTHREADS B-6 to B-7
CDR_MAX_DYNAMIC_LOGS
B-8
CDR_NIFCOMPRESS B-9 to
B-10
CDR_QDATA_SBSPACE 4-14,
4-16, 4-21, B-11
CDR_QHDR_DBSPACE 4-13,
4-20, B-12
CDR_QUEUEMEM 4-12, 4-20,
B-13
CDR_SBSPACE 6-5
CDR_SERIAL 4-21, B-14
configuration B-1 to B-20
DBSERVERALIASES 4-20, B-1
DBSERVERNAME 4-20, B-1
ENCRYPT_CDR B-15
ENCRYPT_CIPHER B-16
ENCRYPT_MAC B-18
ENCRYPT_MACFILE B-19
ENCRYPT_SWITCH B-20
LOGGING 4-15
LTXEHWM 4-11
LTXHWM 4-11
setting in ONCONFIG file 2-12,
4-20
Parent database server. definition
of 3-20
Parent-child
definition of 3-20
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P
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Participant definition
contents 6-8
example 6-9
Participant modifiers
description of A-88
restrictions 2-26, A-91
Participant type
changing 6-15
default 6-9
Primary 6-9
Target 6-9
Participants
adding to replicates 6-15
changing mode A-48
defining 6-8, A-88
definition of 2-6, 6-3, A-88
deleting from replicates 6-15
modifier A-90
owner option A-89
primary option A-89
read-only option A-89
specifying type A-89
update-anywhere 6-9
Pathnames
ATS and RIS directories 4-19
dbspaces 4-13
sbspaces 4-15
Pending state, description of A-40
Performance
Enterprise Replication 1-6
Permitted SQL statements 2-17
ping command, testing network
connection 4-9
Planning
considerations 2-8
for disk space requirements 4-10
Platform icons Intro-10
Port numbers, services file 4-5
Preparing
consistent data 4-22
data for replication
description of 4-22
example of 4-29 to 4-30
database server
environment 4-19
disk, for Enterprise
Replication 4-10
for UDR replication 4-25
for UDT replication 4-25
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hosts file 4-4
logging databases 4-26
network environment 4-3
services file 4-4
SQLHOSTS connectivity
information F-3
tables for conflict resolution 4-25
to use ATS 9-4
to use RIS 9-9
Preventing DDRBLOCK mode 9-14
Preventing memory queues from
overflowing 9-12
Primary
option A-89
participant type 6-9
primary 2-26
Primary conflict-resolution
rule 3-11, 3-12
PRIMARY KEY constraint 2-11
See also
IBM Informix Guide to Database
Design and Implementation
IBM Informix Guide to SQL:
Syntax.
Primary keys
and SERIAL data types 2-12
constraints 2-11
modifying column 2-16
removing constraint 2-16
replicating changed columns 6-12
UDT columns 2-26
updates 1-13
Primary-target
example E-3
replication systems
business models 3-4
combining with HDR 5-4
considerations 3-8
definition of 3-3
Problems, solving
configuration 9-17 to 9-19
Procedure conflict-resolution
rule A-40
Product icons Intro-10
Program group
Documentation notes Intro-16
Release notes Intro-16
Properties, replicate sets 8-6
--prune option, cdr error A-35
A
B
C
D
E
F
G
H
Q
QUEUE column, cdr list server
output A-46
Queues. See Memory queues.
Quiescent state
description of A-40
server A-45
R
RAW tables, unsupported 2-10
rdate command, synchronizing
clocks 2-18
Read-only
option A-89
participant type. See Target
participant type.
Receive queues
definition of 1-14, 4-12
See also Memory queues.
Recording failed transactions, in
ATS files 9-4
Recreating
Enterprise Replication objects 2-9
replicate sets 8-8
replicates 7-10
replication servers 7-7
Reestablishing network
connections 7-12
Referential constraints 8-4
and time-based replication 6-11
Referential integrity, and replicate
sets 8-4
regedt32 program and sqlhosts
registry F-4
Registering UDTs 2-25
Release notes Intro-15
Release notes, program
item Intro-16
Reliable Queue Manager, definition
of 4-12
Removing primary key
constraint 2-16
RENAME TABLE statement 2-16
Renaming columns 2-16
Replicate information
storage 4-13
I
J
K
L
M
N
O
P
Q
R
Replicate sets
adding and deleting
replicates 8-9
changing replication
frequency 8-10
changing state A-61
--connect option 8-3
creating 8-4
customizing 8-5
defining A-16
definition of 2-6, 8-3
deleting 8-8, A-26
examples A-61, A-70, A-76, A-80
exclusive 8-4
frequency 8-5
listing A-42
managing 8-6 to 8-8
modifying 8-9 to 8-10, A-53
non-exclusive 8-5
recreating 8-8
referential constraints 6-11
resuming 8-8, A-61
starting 8-7, A-69
stopping 8-7, A-75
supported versions 8-3, A-16
suspending 8-7, A-79
viewing properties 8-6
Replicates
activating
ATS A-13
RIS A-13
active state 7-8
adding
participants A-4
to replicate sets 8-9
CONFLICT field A-40
conflict options A-11
customizing 6-7
defining 6-7 to 6-14, A-10
definition of 2-6, 6-3
deleting
from global catalog 7-10, A-24
from replicate sets 8-9
participants A-4
displaying information
about A-40
FREQUENCY field A-41
inactive state 7-8
listing A-38
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managing 7-7 to 7-10
modifying 6-15, A-48
recreating 7-10
resuming 7-10, A-59
exclusive replicate sets 7-10
starting 7-8, A-67
exclusive replicate sets 7-8
STATE field A-40
stopping 7-8, A-73
exclusive replicate sets 7-9
suspending 7-9, A-77
exclusive replicate sets 7-9
viewing properties 7-7
Replicating
changed columns only 6-11, 6-12
extensible data types
considerations 2-26
floating-point values 6-13
large objects 6-12
multiple references to a smart
large object 2-24
simple large objects 2-20 to 2-24
smart large objects 2-20 to 2-24
table hierarchies 2-26
UDTs 2-25
Replicating data
capturing transactions 1-10
evaluating
data 1-10
row images 1-10
process 1-9
Replication
blocking 4-22
choosing network topology 3-18
environment
considerations 2-17
managing 2-4
examples E-1 to E-14
frequency
changing 6-15, 8-10
replicate sets 8-5
specifying 6-10
models
primary-target 1-4
update-anywhere 1-4
order error, definition of 1-19
restarting 7-5
stopping 7-4
suspending 7-5
Index 13
A
B
C
D
E
F
G
tree, illustrated 3-21
volume 2-14
Replication servers 2-5
connecting to 7-4
customizing 6-6
defining 6-3, 6-5, A-19
definition of 2-5, 6-3
deleting 7-6, A-28
listing A-44
managing 7-3 to 7-7
modifying 6-14 to 6-16, A-55
recreating 7-7
resuming 7-6
resynchronizing 6-16
state, definition of 7-3
suspending A-81
synchronizing 6-6
troubleshooting 9-13
viewing attributes 7-4
Replication systems
high-availability 5-3
primary-target 3-3, 3-8
supported by Enterprise
Replication 3-3
update-anywhere 3-8, 3-9
Replication topologies
forest of trees 3-22
fully-connected 3-19
hierarchical 3-19
hierarchical tree 3-21
terminology 3-20
Requirements, disk space
delete tables 4-11
logical log files 4-10
message queue spooling 4-12
planning for 4-10
shadow columns 4-12
Restarting replication 7-5
Restoring databases,
considerations 2-9
Restrictions
cdr modify replicate A-49
participant modifiers A-91
Resuming
data delivery
for replicate sets A-61
for replicates A-59
for replication servers A-63
replicate sets 8-8
H
I
J
K
L
M
N
O
P
Q
R
suspended
replicates 7-10
replication servers 7-6
Resynchronizing replication
servers 6-16
Return codes, description of A-92
.rhosts file 4-5
RIS
activating A-13, A-22
capacity planning 4-19
filenames, description of 9-10
modifying directory 6-14
specifying directory 6-6, A-21,
A-55
RIS files
BLOB and CLOB
information 9-12
BYTE and TEXT data 9-11
changed column
information 9-12
configuring 6-11
description of 9-9
preparing to use 9-9
UDT information 9-12
--ris option 6-6, 6-11, 9-9, A-13
cdr define server A-22
cdr modify replicate A-50
cdr modify server A-56
root dbspace, transaction
records 4-13
Root servers
definition of 3-20
global catalog 2-6, 4-8
SQLHOSTS information 4-8
Routines, application-specific 3-16
Row conflict resolution scope 3-13,
3-17, 6-10, 9-4
Row data
creating sbspace for 4-14
storage 4-13
Row Information Spooling. See RIS.
Rowids, adding and dropping 2-16
Rows, replicating entire 6-12
RQM. See Reliable Queue Manager.
RRD label, ATS files 9-6
RRH label, ATS files 9-6
RRS label, ATS files 9-6
Rules
conflict resolution 3-11
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for extensible data types 2-26
for simple large objects 2-22
smart large objects 2-23
time-stamp 3-14
See also Conflict resolution.
S
Sample-code conventions Intro-13
Sbspaces 2-20
grouper paging file 4-18
guidelines for spooled data 4-14
inconsistent replicated data 2-20
increasing sizes 9-17
invalid 6-5
monitoring disk usage 9-16
pathname limitations 4-15
row data 4-14 to 4-18
spooled row data 4-13, 4-14
See also
IBM Informix Dynamic Server
Administrator’s Guide.
IBM Informix Administrator’s
Reference.
SBSPACETEMP parameter 4-18
Scope
definition of 3-17
row 3-13, 3-17
transaction 3-13
See also Conflict resolution.
--scope option 6-10, A-12
Scope options A-11
Secondary conflict-resolution
rule 3-11
Security
See Encryption.
SELECT statement
considerations A-91
limitations A-91
participant modifier A-90
with shadow columns 4-27
Send queues
definition of 1-14, 4-12
See also Memory queues.
--seq option, cdr error A-35
Sequence objects 2-14
SERIAL data types 2-12, 2-19
SERIAL8 data types 2-12, 2-19
A
B
C
D
E
F
G
H
Server administrator, Enterprise
Replication 2-4
SERVER column, cdr list server
output A-45
Server connections, stopping A-32
Server definitions, global
catalog 2-7
Server groups. See Database server
groups.
Server state, global catalog 2-7
Server. See Database servers.
servicename, description of 4-7
services file
example 4-5
preparing 4-4
Sets. See Replicate sets.
Setting
AVG_LO_SIZE 4-15
CDR_QDATA_SBSPACE 4-16
environment variables 4-20
idle timeout 6-6
LOGGING parameter 4-15
Setting up
error logging 6-11
SQLHOSTS file 4-5
SQLHOSTS registry key F-3
setup program, for SQLHOSTS
registry F-1
Shadow columns
ADD CRCOLS 4-25
adding 2-16
behavior with BEGIN WORK
WITHOUT
REPLICATION 4-23
cdrserver 2-11, 2-21
cdrtime 2-11, 2-21
conflict resolution rules 3-11
creating 2-11, 4-12, 9-18
defining 4-25
disk space requirements 4-10,
4-12
dropping 2-16, 4-26
High-Performance Loader 4-27
in ATS files 9-6
loading and unloading data 4-27
UNLOAD statement 4-28
updating with DB-Access 4-24
WITH CRCOLS statement 4-25
I
J
K
L
M
N
O
P
Q
R
Simple large objects
conflict resolution 2-21
cross-replication 2-21
replicating 2-20 to 2-24
from blobspaces 2-20
from tblspaces 2-20
SPL conflict resolution 2-22
storing
in blobspaces 2-20
in tblspaces 2-20
timestamp conflict
resolution 2-21
Size
storage spaces 9-16
transaction record dbspace 4-13
SMALLFLOAT data type 6-13
Smart blobs. See Smart large objects.
Smart large objects
cross replication 2-21
in ATS files 9-8
multiple references to 2-24
replicating 2-20 to 2-24
replicating only changed
columns 6-12
specifying default behavior 4-15
SPL conflict resolution 2-23
spooled row data 4-14
storing in sbspaces 2-20
SMI tables D-1 to D-17
summary D-1
syscdrack_buf D-3
syscdrack_txn D-3
syscdrctrl_buf D-3
syscdrctrl_txn D-4
syscdrerror D-4, D-13
syscdrpart D-5
syscdrprog D-5
syscdrq D-6
syscdrqueued D-7
syscdrrecv_buf D-7
syscdrrecv_txn D-7
syscdrrepl D-8
syscdrreplset D-9
syscdrs D-10
syscdrsend_buf D-11
syscdrsend_txn D-11
syscdrserver D-12
syscdrtx D-13
Software dependencies Intro-4
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Solving configuration
problems 9-17 to 9-19
Specifying
ATS directory A-21, A-55
conflict resolution
options A-11
rules 6-10
scope 6-10
database server type 6-7
default behavior for smart large
objects 4-15
idle timeout A-21
location
ATS directory 6-6
RIS directory 6-6
replication frequency 6-10
RIS directory A-21, A-55
SPL conflict resolution
limitations 3-15
rule 3-11, 3-14, 6-10
simple large objects 2-22
smart large objects 2-23
SPL routines
arguments 3-15
considerations 3-16
delete table 3-15
information passed by Enterprise
Replication 3-15
limitations for conflict
resolution 2-26
nonoptimized 3-17
optimized 3-17
Spooled row data sbspace
dropping 4-17
logging and HDR 5-11
Spooled row data sbspaces
changing logging mode 4-17
guidelines for creating 4-14
logging mode 4-16
Spooled transactions 9-12
definition of 4-13
storage 4-13
troubleshooting 9-13
Spooling
directories
ATS and RIS 3-12
capacity planning 4-19
default 4-19
more than usual, causes of 9-15
Index 15
A
B
C
D
E
F
G
H
planning for disk space 4-12
SQL code Intro-13
SQL statements
forbidden 2-16
limited 2-16
permitted 2-17
supported 2-15
See also IBM Informix Guide to SQL:
Syntax.
SQLHOSTS
hierarchical routine
topologies 4-8
INFORMIXSQLHOSTS
environment variable F-2
leaf servers 4-8
nonroot servers 4-8
on UNIX E-2
on Windows F-1
preparing connectivity
information F-3
registry key F-1, F-8
local F-2
setting up F-3
shared F-2
root servers 4-8
setting up with ISA 4-8, F-3
specifying registry host
machine 4-20
SQLHOSTS file
database server groups for
HDR 5-9
encryption, setting up for 4-8
example 4-6
format 9-18
server group 2-5
setting up 4-5
specifying location 4-20
UNIX 4-6
Starting
data delivery
for replicate sets A-69
for replicates A-67
Enterprise Replication A-65
replicate sets 8-7
replicates 7-8
starts command 6-4
STATE column, cdr list server
output A-45
I
J
K
L
M
N
O
P
Q
R
STATE field, cdr list replicate
output A-40
Statements
ALTER TABLE 4-26
BEGIN WORK WITHOUT
REPLICATION 4-22
CREATE TABLE 4-26
DROP CRCOLS 4-26
LOAD 4-26, 4-28
SELECT 4-27
SQL, supported 2-15
UNLOAD 4-28
WITH CRCOLS 4-25
States
active 7-8
inactive 7-8
STATUS column, cdr list server
output A-45
Stopping
data capture
for replicate sets A-75
for replicates A-73
Enterprise Replication A-71
replicate sets 8-7
replicates 7-8
replication 7-4
server connection A-32
Storage
delete tables 4-11
increasing size of spaces 9-16
spooled transactions 4-13
Stored procedure language. See SPL
routines.
stores_demo database Intro-5
Storing data in tblspaces 2-21
streamread support functions 2-25,
4-25
streamwrite support
functions 2-25, 4-25
Summary
commands A-2
SMI tables D-1
superstores_demo database Intro-5
Support functions
for replicating UDTs 2-25, 4-25
streamread 2-25, 4-25
streamwrite 2-25, 4-25
writing 2-25, 4-25
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See also IBM Informix DataBlade
API Programmer’s Manual.
Supported
data types 2-19
database servers 2-8
SQL statements 2-15
table types 2-10
Suspended state
description of A-40
server A-45
Suspending
data delivery
for replicate sets A-79
for replicates A-77
database servers A-81
replicate sets 8-7
replicates 7-9
replication 7-5
Switching logical log files 4-10
--sync option 6-6, A-20
Synchronization
servers 3-21, 6-6
times 3-14
Synchronizing
clocks
net time command 2-18
rdate command 2-18
data
onload and onunload
utilities 4-28
using DB-Access 4-24
using ESQL/C 4-24
global catalog 6-6
operating system times 2-17, 9-18
Synchronous data replication
definition of 1-4
two-phase commit
technology 1-4
Synonyms, and Enterprise
Replication 2-8
Syntax
command-line utility A-83
participant definition A-88
syscdr database 2-6
syscdrack_buf table D-3
syscdrack_txn table D-3
syscdrctrl_buf table D-3
syscdrctrl_txn table D-4
syscdrerror table D-4, D-13
A
B
C
D
E
F
G
H
syscdrpart table D-5
syscdrprog table D-5
syscdrq table D-6
syscdrqueued table D-7
syscdrrecv_buf table D-7
syscdrrecv_txn table D-7
syscdrrepl table D-8
syscdrreplset table D-9
syscdrs table D-10
syscdrsend_buf table D-11
syscdrsend_txn table D-11
syscdrserver table D-12
syscdrtx table D-13
sysmaster database, SMI tables D-1
System Monitoring Interface. See
SMI tables.
System names, in hosts file 4-4
System requirements
database Intro-4
software Intro-4
T
Table hierarchies, replicating 2-26
Table types, unsupported 2-10
Tables
buffer D-17
designing, considerations 2-9
locking 2-15
preparing for conflict
resolution 4-25
RAW 2-10
SMI D-1 to D-17
temporary 2-10
transaction D-16
unsupported 2-10
Target participant type 6-9
Tblspaces 2-20
storing BYTE and TEXT
data 2-20, 2-21
Temporary tables 2-10
Terminology
command-line utility A-83
Enterprise Replication 2-5
Enterprise Replication servers 2-5
global catalog 2-6
hierarchical topology 3-20
participant 2-6
I
J
K
L
M
N
O
P
Q
R
replicate 2-6
replicate set 2-6
replication servers 2-5
Testing
network environment 4-9
trusted environment 4-9
TEXT data
ATS files 9-7
distributing 2-24
RIS files 9-11
SPL conflict resolution 2-22
storing in tblspaces 2-21
types, loading 4-27
Threads used by Enterprise
Replication C-3
Time formats A-93
Time synchronization 2-17, 3-14,
9-18
Timeout
idle, setting 6-6
status, replication servers A-45
Timestamp conflict resolution
rule 3-11, 3-13, 6-10, A-40
database action 3-14
definition of 3-13
delete table 4-11
simple large objects 2-21
Tip icons Intro-10
Tools for loading and unloading
data 4-26
Topology, choosing network 3-18
Transaction
buffers, spooling to disk 4-13,
9-12
constraint checking 3-18
evaluation examples 1-15 to 1-18
evaluation logic 1-11
processing 2-14
tables D-16
Transaction conflict resolution
scope 3-13, 3-17, 6-10
Transaction records
default dbspace 4-13
storage 4-13
Transactional integrity 3-17
Transactions
distributed 2-14
failed, ATS and RIS files 6-11, 9-3
large 2-15
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Tree topology, illustrated 3-21
Tree, definition of 3-20
Triggers
activating A-14
changing 6-15
data capture 1-5
definition of 1-5
enabling 6-14
errors with Enterprise
Replication 2-13
firing A-51
in primary key updates 1-13
permissions A-89
transaction capture 1-5
Troubleshooting
configuration
problems 9-17 to 9-19
spooled transactions 9-13
Trusted environment
configuring 4-5
testing 4-9
Two-phase commit
definition of 1-4
distributed transactions 2-14
TXH label, ATS files 9-6
TZ environment variable A-93
U
UDRs
HDR servers, preparing 5-10
installing 4-25
preparing to replicate 4-25
registering 4-25
SPL conflict resolution 3-15
UDTs
columns, primary key 2-26
HDR servers, preparing 5-10
in ATS files 9-8
information in ATS files 9-8
information in RIS files 9-12
installing 4-25
installing and registering 2-25
loading with deluxe mode 4-27
preparing to replicate 4-25
registering 4-25
replicating
only changed columns 6-12
Index 17
A
B
C
D
E
F
G
H
preparation 2-25
spooled row data 4-14
support for 2-25
support functions 2-25
Unbuffered logging 2-10, 4-26
UNIX
database server groups 4-6
oninit command 6-4
onmode command 6-4
SQLHOSTS file 4-6, 4-20
UNLOAD statement 4-28
See also IBM Informix Guide to SQL:
Syntax.
unload utility 4-28
Unloading data 4-26, 4-27
Unsupported table types 2-10
Update-anywhere
examples E-6
participants 6-9
replication system
combining with HDR 5-5
replication systems, description
of 3-8
Updates
multiple-row images 1-13
primary key 1-13
WHERE clause column 1-13
Updating shadow columns 4-24
UPSERTs
definition of 6-12
replicating only changed
columns 6-12
User-defined data types. See UDTs.
User-defined routines. See UDRs.
Users, informix 2-4
Using
canonical format 6-13
IEEE floating point format 6-13
Utilities
dbexport 4-28
dbimport 4-28
onload 4-28
onunload 4-26, 4-28
unload 4-28
I
J
K
L
M
N
O
P
Q
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Variables. See Environment
variables.
Viewing
network connection status 7-11
replicate attributes 7-7
replicate set attributes 8-6
replication server attributes 7-4
Views, and Enterprise
Replication 2-8
Virtual columns, support for 2-26
W
Warning icons Intro-10
WHERE clause
column updates 1-13
Windows
database server groups 4-7
Informix-Admin group 2-4
onmode command 6-4
SQLHOSTS registry host 4-20
starts command 6-4
WITH CRCOLS statement
defining shadow columns 4-25
Workflow replication business
model 3-7
Workload partitioning business
model 3-6
Writing
support functions 2-25
transaction buffers to disk 9-12
X
X/Open compliance level Intro-17
Z
--zap option, cdr error A-35
V
Values, sending floating-point 6-13
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